/*
 * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */

package java.util;

import java.io.BufferedWriter;
import java.io.Closeable;
import java.io.IOException;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileNotFoundException;
import java.io.Flushable;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintStream;
import java.io.UnsupportedEncodingException;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.math.MathContext;
import java.math.RoundingMode;
import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.UnsupportedCharsetException;
import java.text.DateFormatSymbols;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.text.NumberFormat;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import java.time.DateTimeException;
import java.time.Instant;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.time.temporal.ChronoField;
import java.time.temporal.TemporalAccessor;
import java.time.temporal.TemporalQueries;

import sun.misc.DoubleConsts;
import sun.misc.FormattedFloatingDecimal;

/**
 * An interpreter for printf-style format strings.  This class provides support
 * for layout justification and alignment, common formats for numeric, string,
 * and date/time data, and locale-specific output.  Common Java types such as
 * {@code byte}, {@link java.math.BigDecimal BigDecimal}, and {@link Calendar}
 * are supported.  Limited formatting customization for arbitrary user types is
 * provided through the {@link Formattable} interface.
 *
 * <p> Formatters are not necessarily safe for multithreaded access.  Thread
 * safety is optional and is the responsibility of users of methods in this
 * class.
 *
 * <p> Formatted printing for the Java language is heavily inspired by C's
 * {@code printf}.  Although the format strings are similar to C, some
 * customizations have been made to accommodate the Java language and exploit
 * some of its features.  Also, Java formatting is more strict than C's; for
 * example, if a conversion is incompatible with a flag, an exception will be
 * thrown.  In C inapplicable flags are silently ignored.  The format strings
 * are thus intended to be recognizable to C programmers but not necessarily
 * completely compatible with those in C.
 *
 * <p> Examples of expected usage:
 *
 * <blockquote><pre>
 *   StringBuilder sb = new StringBuilder();
 *   // Send all output to the Appendable object sb
 *   Formatter formatter = new Formatter(sb, Locale.US);
 *
 *   // Explicit argument indices may be used to re-order output.
 *   formatter.format("%4$2s %3$2s %2$2s %1$2s", "a", "b", "c", "d")
 *   // -&gt; " d  c  b  a"
 *
 *   // Optional locale as the first argument can be used to get
 *   // locale-specific formatting of numbers.  The precision and width can be
 *   // given to round and align the value.
 *   formatter.format(Locale.FRANCE, "e = %+10.4f", Math.E);
 *   // -&gt; "e =    +2,7183"
 *
 *   // The '(' numeric flag may be used to format negative numbers with
 *   // parentheses rather than a minus sign.  Group separators are
 *   // automatically inserted.
 *   formatter.format("Amount gained or lost since last statement: $ %(,.2f",
 *                    balanceDelta);
 *   // -&gt; "Amount gained or lost since last statement: $ (6,217.58)"
 * </pre></blockquote>
 *
 * <p> Convenience methods for common formatting requests exist as illustrated
 * by the following invocations:
 *
 * <blockquote><pre>
 *   // Writes a formatted string to System.out.
 *   System.out.format("Local time: %tT", Calendar.getInstance());
 *   // -&gt; "Local time: 13:34:18"
 *
 *   // Writes formatted output to System.err.
 *   System.err.printf("Unable to open file '%1$s': %2$s",
 *                     fileName, exception.getMessage());
 *   // -&gt; "Unable to open file 'food': No such file or directory"
 * </pre></blockquote>
 *
 * <p> Like C's {@code sprintf(3)}, Strings may be formatted using the static
 * method {@link String#format(String, Object...) String.format}:
 *
 * <blockquote><pre>
 *   // Format a string containing a date.
 *   import java.util.Calendar;
 *   import java.util.GregorianCalendar;
 *   import static java.util.Calendar.*;
 *
 *   Calendar c = new GregorianCalendar(1995, MAY, 23);
 *   String s = String.format("Duke's Birthday: %1$tb %1$te, %1$tY", c);
 *   // -&gt; s == "Duke's Birthday: May 23, 1995"
 * </pre></blockquote>
 *
 * <h3><a name="org">Organization</a></h3>
 *
 * <p> This specification is divided into two sections.  The first section, <a
 * href="#summary">Summary</a>, covers the basic formatting concepts.  This
 * section is intended for users who want to get started quickly and are
 * familiar with formatted printing in other programming languages.  The second
 * section, <a href="#detail">Details</a>, covers the specific implementation
 * details.  It is intended for users who want more precise specification of
 * formatting behavior.
 *
 * <h3><a name="summary">Summary</a></h3>
 *
 * <p> This section is intended to provide a brief overview of formatting
 * concepts.  For precise behavioral details, refer to the <a
 * href="#detail">Details</a> section.
 *
 * <h4><a name="syntax">Format String Syntax</a></h4>
 *
 * <p> Every method which produces formatted output requires a <i>format
 * string</i> and an <i>argument list</i>.  The format string is a {@link
 * String} which may contain fixed text and one or more embedded <i>format
 * specifiers</i>.  Consider the following example:
 *
 * <blockquote><pre>
 *   Calendar c = ...;
 *   String s = String.format("Duke's Birthday: %1$tm %1$te,%1$tY", c);
 * </pre></blockquote>
 *
 * This format string is the first argument to the {@code format} method.  It
 * contains three format specifiers "{@code %1$tm}", "{@code %1$te}", and
 * "{@code %1$tY}" which indicate how the arguments should be processed and
 * where they should be inserted in the text.  The remaining portions of the
 * format string are fixed text including {@code "Dukes Birthday: "} and any
 * other spaces or punctuation.
 *
 * The argument list consists of all arguments passed to the method after the
 * format string.  In the above example, the argument list is of size one and
 * consists of the {@link java.util.Calendar Calendar} object {@code c}.
 *
 * <ul>
 *
 * <li> The format specifiers for general, character, and numeric types have
 * the following syntax:
 *
 * <blockquote><pre>
 *   %[argument_index$][flags][width][.precision]conversion
 * </pre></blockquote>
 *
 * <p> The optional <i>argument_index</i> is a decimal integer indicating the
 * position of the argument in the argument list.  The first argument is
 * referenced by "{@code 1$}", the second by "{@code 2$}", etc.
 *
 * <p> The optional <i>flags</i> is a set of characters that modify the output
 * format.  The set of valid flags depends on the conversion.
 *
 * <p> The optional <i>width</i> is a positive decimal integer indicating
 * the minimum number of characters to be written to the output.
 *
 * <p> The optional <i>precision</i> is a non-negative decimal integer usually
 * used to restrict the number of characters.  The specific behavior depends on
 * the conversion.
 *
 * <p> The required <i>conversion</i> is a character indicating how the
 * argument should be formatted.  The set of valid conversions for a given
 * argument depends on the argument's data type.
 *
 * <li> The format specifiers for types which are used to represents dates and
 * times have the following syntax:
 *
 * <blockquote><pre>
 *   %[argument_index$][flags][width]conversion
 * </pre></blockquote>
 *
 * <p> The optional <i>argument_index</i>, <i>flags</i> and <i>width</i> are
 * defined as above.
 *
 * <p> The required <i>conversion</i> is a two character sequence.  The first
 * character is {@code 't'} or {@code 'T'}.  The second character indicates
 * the format to be used.  These characters are similar to but not completely
 * identical to those defined by GNU {@code date} and POSIX
 * {@code strftime(3c)}.
 *
 * <li> The format specifiers which do not correspond to arguments have the
 * following syntax:
 *
 * <blockquote><pre>
 *   %[flags][width]conversion
 * </pre></blockquote>
 *
 * <p> The optional <i>flags</i> and <i>width</i> is defined as above.
 *
 * <p> The required <i>conversion</i> is a character indicating content to be
 * inserted in the output.
 *
 * </ul>
 *
 * <h4> Conversions </h4>
 *
 * <p> Conversions are divided into the following categories:
 *
 * <ol>
 *
 * <li> <b>General</b> - may be applied to any argument
 * type
 *
 * <li> <b>Character</b> - may be applied to basic types which represent
 * Unicode characters: {@code char}, {@link Character}, {@code byte}, {@link
 * Byte}, {@code short}, and {@link Short}. This conversion may also be
 * applied to the types {@code int} and {@link Integer} when {@link
 * Character#isValidCodePoint} returns {@code true}
 *
 * <li> <b>Numeric</b>
 *
 * <ol>
 *
 * <li> <b>Integral</b> - may be applied to Java integral types: {@code byte},
 * {@link Byte}, {@code short}, {@link Short}, {@code int} and {@link
 * Integer}, {@code long}, {@link Long}, and {@link java.math.BigInteger
 * BigInteger} (but not {@code char} or {@link Character})
 *
 * <li><b>Floating Point</b> - may be applied to Java floating-point types:
 * {@code float}, {@link Float}, {@code double}, {@link Double}, and {@link
 * java.math.BigDecimal BigDecimal}
 *
 * </ol>
 *
 * <li> <b>Date/Time</b> - may be applied to Java types which are capable of
 * encoding a date or time: {@code long}, {@link Long}, {@link Calendar},
 * {@link Date} and {@link TemporalAccessor TemporalAccessor}
 *
 * <li> <b>Percent</b> - produces a literal {@code '%'}
 * (<tt>'&#92;u0025'</tt>)
 *
 * <li> <b>Line Separator</b> - produces the platform-specific line separator
 *
 * </ol>
 *
 * <p> The following table summarizes the supported conversions.  Conversions
 * denoted by an upper-case character (i.e. {@code 'B'}, {@code 'H'},
 * {@code 'S'}, {@code 'C'}, {@code 'X'}, {@code 'E'}, {@code 'G'},
 * {@code 'A'}, and {@code 'T'}) are the same as those for the corresponding
 * lower-case conversion characters except that the result is converted to
 * upper case according to the rules of the prevailing {@link java.util.Locale
 * Locale}.  The result is equivalent to the following invocation of {@link
 * String#toUpperCase()}
 *
 * <pre>
 *    out.toUpperCase() </pre>
 *
 * <table cellpadding=5 summary="genConv">
 *
 * <tr><th valign="bottom"> Conversion
 * <th valign="bottom"> Argument Category
 * <th valign="bottom"> Description
 *
 * <tr><td valign="top"> {@code 'b'}, {@code 'B'}
 * <td valign="top"> general
 * <td> If the argument <i>arg</i> is {@code null}, then the result is
 * "{@code false}".  If <i>arg</i> is a {@code boolean} or {@link
 * Boolean}, then the result is the string returned by {@link
 * String#valueOf(boolean) String.valueOf(arg)}.  Otherwise, the result is
 * "true".
 *
 * <tr><td valign="top"> {@code 'h'}, {@code 'H'}
 * <td valign="top"> general
 * <td> If the argument <i>arg</i> is {@code null}, then the result is
 * "{@code null}".  Otherwise, the result is obtained by invoking
 * {@code Integer.toHexString(arg.hashCode())}.
 *
 * <tr><td valign="top"> {@code 's'}, {@code 'S'}
 * <td valign="top"> general
 * <td> If the argument <i>arg</i> is {@code null}, then the result is
 * "{@code null}".  If <i>arg</i> implements {@link Formattable}, then
 * {@link Formattable#formatTo arg.formatTo} is invoked. Otherwise, the
 * result is obtained by invoking {@code arg.toString()}.
 *
 * <tr><td valign="top">{@code 'c'}, {@code 'C'}
 * <td valign="top"> character
 * <td> The result is a Unicode character
 *
 * <tr><td valign="top">{@code 'd'}
 * <td valign="top"> integral
 * <td> The result is formatted as a decimal integer
 *
 * <tr><td valign="top">{@code 'o'}
 * <td valign="top"> integral
 * <td> The result is formatted as an octal integer
 *
 * <tr><td valign="top">{@code 'x'}, {@code 'X'}
 * <td valign="top"> integral
 * <td> The result is formatted as a hexadecimal integer
 *
 * <tr><td valign="top">{@code 'e'}, {@code 'E'}
 * <td valign="top"> floating point
 * <td> The result is formatted as a decimal number in computerized
 * scientific notation
 *
 * <tr><td valign="top">{@code 'f'}
 * <td valign="top"> floating point
 * <td> The result is formatted as a decimal number
 *
 * <tr><td valign="top">{@code 'g'}, {@code 'G'}
 * <td valign="top"> floating point
 * <td> The result is formatted using computerized scientific notation or
 * decimal format, depending on the precision and the value after rounding.
 *
 * <tr><td valign="top">{@code 'a'}, {@code 'A'}
 * <td valign="top"> floating point
 * <td> The result is formatted as a hexadecimal floating-point number with
 * a significand and an exponent. This conversion is <b>not</b> supported
 * for the {@code BigDecimal} type despite the latter's being in the
 * <i>floating point</i> argument category.
 *
 * <tr><td valign="top">{@code 't'}, {@code 'T'}
 * <td valign="top"> date/time
 * <td> Prefix for date and time conversion characters.  See <a
 * href="#dt">Date/Time Conversions</a>.
 *
 * <tr><td valign="top">{@code '%'}
 * <td valign="top"> percent
 * <td> The result is a literal {@code '%'} (<tt>'&#92;u0025'</tt>)
 *
 * <tr><td valign="top">{@code 'n'}
 * <td valign="top"> line separator
 * <td> The result is the platform-specific line separator
 *
 * </table>
 *
 * <p> Any characters not explicitly defined as conversions are illegal and are
 * reserved for future extensions.
 *
 * <h4><a name="dt">Date/Time Conversions</a></h4>
 *
 * <p> The following date and time conversion suffix characters are defined for
 * the {@code 't'} and {@code 'T'} conversions.  The types are similar to but
 * not completely identical to those defined by GNU {@code date} and POSIX
 * {@code strftime(3c)}.  Additional conversion types are provided to access
 * Java-specific functionality (e.g. {@code 'L'} for milliseconds within the
 * second).
 *
 * <p> The following conversion characters are used for formatting times:
 *
 * <table cellpadding=5 summary="time">
 *
 * <tr><td valign="top"> {@code 'H'}
 * <td> Hour of the day for the 24-hour clock, formatted as two digits with
 * a leading zero as necessary i.e. {@code 00 - 23}.
 *
 * <tr><td valign="top">{@code 'I'}
 * <td> Hour for the 12-hour clock, formatted as two digits with a leading
 * zero as necessary, i.e.  {@code 01 - 12}.
 *
 * <tr><td valign="top">{@code 'k'}
 * <td> Hour of the day for the 24-hour clock, i.e. {@code 0 - 23}.
 *
 * <tr><td valign="top">{@code 'l'}
 * <td> Hour for the 12-hour clock, i.e. {@code 1 - 12}.
 *
 * <tr><td valign="top">{@code 'M'}
 * <td> Minute within the hour formatted as two digits with a leading zero
 * as necessary, i.e.  {@code 00 - 59}.
 *
 * <tr><td valign="top">{@code 'S'}
 * <td> Seconds within the minute, formatted as two digits with a leading
 * zero as necessary, i.e. {@code 00 - 60} ("{@code 60}" is a special
 * value required to support leap seconds).
 *
 * <tr><td valign="top">{@code 'L'}
 * <td> Millisecond within the second formatted as three digits with
 * leading zeros as necessary, i.e. {@code 000 - 999}.
 *
 * <tr><td valign="top">{@code 'N'}
 * <td> Nanosecond within the second, formatted as nine digits with leading
 * zeros as necessary, i.e. {@code 000000000 - 999999999}.
 *
 * <tr><td valign="top">{@code 'p'}
 * <td> Locale-specific {@linkplain
 * java.text.DateFormatSymbols#getAmPmStrings morning or afternoon} marker
 * in lower case, e.g."{@code am}" or "{@code pm}". Use of the conversion
 * prefix {@code 'T'} forces this output to upper case.
 *
 * <tr><td valign="top">{@code 'z'}
 * <td> <a href="http://www.ietf.org/rfc/rfc0822.txt">RFC&nbsp;822</a>
 * style numeric time zone offset from GMT, e.g. {@code -0800}.  This
 * value will be adjusted as necessary for Daylight Saving Time.  For
 * {@code long}, {@link Long}, and {@link Date} the time zone used is
 * the {@linkplain TimeZone#getDefault() default time zone} for this
 * instance of the Java virtual machine.
 *
 * <tr><td valign="top">{@code 'Z'}
 * <td> A string representing the abbreviation for the time zone.  This
 * value will be adjusted as necessary for Daylight Saving Time.  For
 * {@code long}, {@link Long}, and {@link Date} the  time zone used is
 * the {@linkplain TimeZone#getDefault() default time zone} for this
 * instance of the Java virtual machine.  The Formatter's locale will
 * supersede the locale of the argument (if any).
 *
 * <tr><td valign="top">{@code 's'}
 * <td> Seconds since the beginning of the epoch starting at 1 January 1970
 * {@code 00:00:00} UTC, i.e. {@code Long.MIN_VALUE/1000} to
 * {@code Long.MAX_VALUE/1000}.
 *
 * <tr><td valign="top">{@code 'Q'}
 * <td> Milliseconds since the beginning of the epoch starting at 1 January
 * 1970 {@code 00:00:00} UTC, i.e. {@code Long.MIN_VALUE} to
 * {@code Long.MAX_VALUE}.
 *
 * </table>
 *
 * <p> The following conversion characters are used for formatting dates:
 *
 * <table cellpadding=5 summary="date">
 *
 * <tr><td valign="top">{@code 'B'}
 * <td> Locale-specific {@linkplain java.text.DateFormatSymbols#getMonths
 * full month name}, e.g. {@code "January"}, {@code "February"}.
 *
 * <tr><td valign="top">{@code 'b'}
 * <td> Locale-specific {@linkplain
 * java.text.DateFormatSymbols#getShortMonths abbreviated month name},
 * e.g. {@code "Jan"}, {@code "Feb"}.
 *
 * <tr><td valign="top">{@code 'h'}
 * <td> Same as {@code 'b'}.
 *
 * <tr><td valign="top">{@code 'A'}
 * <td> Locale-specific full name of the {@linkplain
 * java.text.DateFormatSymbols#getWeekdays day of the week},
 * e.g. {@code "Sunday"}, {@code "Monday"}
 *
 * <tr><td valign="top">{@code 'a'}
 * <td> Locale-specific short name of the {@linkplain
 * java.text.DateFormatSymbols#getShortWeekdays day of the week},
 * e.g. {@code "Sun"}, {@code "Mon"}
 *
 * <tr><td valign="top">{@code 'C'}
 * <td> Four-digit year divided by {@code 100}, formatted as two digits
 * with leading zero as necessary, i.e. {@code 00 - 99}
 *
 * <tr><td valign="top">{@code 'Y'}
 * <td> Year, formatted as at least four digits with leading zeros as
 * necessary, e.g. {@code 0092} equals {@code 92} CE for the Gregorian
 * calendar.
 *
 * <tr><td valign="top">{@code 'y'}
 * <td> Last two digits of the year, formatted with leading zeros as
 * necessary, i.e. {@code 00 - 99}.
 *
 * <tr><td valign="top">{@code 'j'}
 * <td> Day of year, formatted as three digits with leading zeros as
 * necessary, e.g. {@code 001 - 366} for the Gregorian calendar.
 *
 * <tr><td valign="top">{@code 'm'}
 * <td> Month, formatted as two digits with leading zeros as necessary,
 * i.e. {@code 01 - 13}.
 *
 * <tr><td valign="top">{@code 'd'}
 * <td> Day of month, formatted as two digits with leading zeros as
 * necessary, i.e. {@code 01 - 31}
 *
 * <tr><td valign="top">{@code 'e'}
 * <td> Day of month, formatted as two digits, i.e. {@code 1 - 31}.
 *
 * </table>
 *
 * <p> The following conversion characters are used for formatting common
 * date/time compositions.
 *
 * <table cellpadding=5 summary="composites">
 *
 * <tr><td valign="top">{@code 'R'}
 * <td> Time formatted for the 24-hour clock as {@code "%tH:%tM"}
 *
 * <tr><td valign="top">{@code 'T'}
 * <td> Time formatted for the 24-hour clock as {@code "%tH:%tM:%tS"}.
 *
 * <tr><td valign="top">{@code 'r'}
 * <td> Time formatted for the 12-hour clock as {@code "%tI:%tM:%tS %Tp"}.
 * The location of the morning or afternoon marker ({@code '%Tp'}) may be
 * locale-dependent.
 *
 * <tr><td valign="top">{@code 'D'}
 * <td> Date formatted as {@code "%tm/%td/%ty"}.
 *
 * <tr><td valign="top">{@code 'F'}
 * <td> <a href="http://www.w3.org/TR/NOTE-datetime">ISO&nbsp;8601</a>
 * complete date formatted as {@code "%tY-%tm-%td"}.
 *
 * <tr><td valign="top">{@code 'c'}
 * <td> Date and time formatted as {@code "%ta %tb %td %tT %tZ %tY"},
 * e.g. {@code "Sun Jul 20 16:17:00 EDT 1969"}.
 *
 * </table>
 *
 * <p> Any characters not explicitly defined as date/time conversion suffixes
 * are illegal and are reserved for future extensions.
 *
 * <h4> Flags </h4>
 *
 * <p> The following table summarizes the supported flags.  <i>y</i> means the
 * flag is supported for the indicated argument types.
 *
 * <table cellpadding=5 summary="genConv">
 *
 * <tr><th valign="bottom"> Flag <th valign="bottom"> General
 * <th valign="bottom"> Character <th valign="bottom"> Integral
 * <th valign="bottom"> Floating Point
 * <th valign="bottom"> Date/Time
 * <th valign="bottom"> Description
 *
 * <tr><td> '-' <td align="center" valign="top"> y
 * <td align="center" valign="top"> y
 * <td align="center" valign="top"> y
 * <td align="center" valign="top"> y
 * <td align="center" valign="top"> y
 * <td> The result will be left-justified.
 *
 * <tr><td> '#' <td align="center" valign="top"> y<sup>1</sup>
 * <td align="center" valign="top"> -
 * <td align="center" valign="top"> y<sup>3</sup>
 * <td align="center" valign="top"> y
 * <td align="center" valign="top"> -
 * <td> The result should use a conversion-dependent alternate form
 *
 * <tr><td> '+' <td align="center" valign="top"> -
 * <td align="center" valign="top"> -
 * <td align="center" valign="top"> y<sup>4</sup>
 * <td align="center" valign="top"> y
 * <td align="center" valign="top"> -
 * <td> The result will always include a sign
 *
 * <tr><td> '&nbsp;&nbsp;' <td align="center" valign="top"> -
 * <td align="center" valign="top"> -
 * <td align="center" valign="top"> y<sup>4</sup>
 * <td align="center" valign="top"> y
 * <td align="center" valign="top"> -
 * <td> The result will include a leading space for positive values
 *
 * <tr><td> '0' <td align="center" valign="top"> -
 * <td align="center" valign="top"> -
 * <td align="center" valign="top"> y
 * <td align="center" valign="top"> y
 * <td align="center" valign="top"> -
 * <td> The result will be zero-padded
 *
 * <tr><td> ',' <td align="center" valign="top"> -
 * <td align="center" valign="top"> -
 * <td align="center" valign="top"> y<sup>2</sup>
 * <td align="center" valign="top"> y<sup>5</sup>
 * <td align="center" valign="top"> -
 * <td> The result will include locale-specific {@linkplain
 * java.text.DecimalFormatSymbols#getGroupingSeparator grouping separators}
 *
 * <tr><td> '(' <td align="center" valign="top"> -
 * <td align="center" valign="top"> -
 * <td align="center" valign="top"> y<sup>4</sup>
 * <td align="center" valign="top"> y<sup>5</sup>
 * <td align="center"> -
 * <td> The result will enclose negative numbers in parentheses
 *
 * </table>
 *
 * <p> <sup>1</sup> Depends on the definition of {@link Formattable}.
 *
 * <p> <sup>2</sup> For {@code 'd'} conversion only.
 *
 * <p> <sup>3</sup> For {@code 'o'}, {@code 'x'}, and {@code 'X'}
 * conversions only.
 *
 * <p> <sup>4</sup> For {@code 'd'}, {@code 'o'}, {@code 'x'}, and
 * {@code 'X'} conversions applied to {@link java.math.BigInteger BigInteger}
 * or {@code 'd'} applied to {@code byte}, {@link Byte}, {@code short}, {@link
 * Short}, {@code int} and {@link Integer}, {@code long}, and {@link Long}.
 *
 * <p> <sup>5</sup> For {@code 'e'}, {@code 'E'}, {@code 'f'},
 * {@code 'g'}, and {@code 'G'} conversions only.
 *
 * <p> Any characters not explicitly defined as flags are illegal and are
 * reserved for future extensions.
 *
 * <h4> Width </h4>
 *
 * <p> The width is the minimum number of characters to be written to the
 * output.  For the line separator conversion, width is not applicable; if it
 * is provided, an exception will be thrown.
 *
 * <h4> Precision </h4>
 *
 * <p> For general argument types, the precision is the maximum number of
 * characters to be written to the output.
 *
 * <p> For the floating-point conversions {@code 'a'}, {@code 'A'}, {@code 'e'},
 * {@code 'E'}, and {@code 'f'} the precision is the number of digits after the
 * radix point.  If the conversion is {@code 'g'} or {@code 'G'}, then the
 * precision is the total number of digits in the resulting magnitude after
 * rounding.
 *
 * <p> For character, integral, and date/time argument types and the percent
 * and line separator conversions, the precision is not applicable; if a
 * precision is provided, an exception will be thrown.
 *
 * <h4> Argument Index </h4>
 *
 * <p> The argument index is a decimal integer indicating the position of the
 * argument in the argument list.  The first argument is referenced by
 * "{@code 1$}", the second by "{@code 2$}", etc.
 *
 * <p> Another way to reference arguments by position is to use the
 * {@code '<'} (<tt>'&#92;u003c'</tt>) flag, which causes the argument for
 * the previous format specifier to be re-used.  For example, the following two
 * statements would produce identical strings:
 *
 * <blockquote><pre>
 *   Calendar c = ...;
 *   String s1 = String.format("Duke's Birthday: %1$tm %1$te,%1$tY", c);
 *
 *   String s2 = String.format("Duke's Birthday: %1$tm %&lt;te,%&lt;tY", c);
 * </pre></blockquote>
 *
 * <hr>
 * <h3><a name="detail">Details</a></h3>
 *
 * <p> This section is intended to provide behavioral details for formatting,
 * including conditions and exceptions, supported data types, localization, and
 * interactions between flags, conversions, and data types.  For an overview of
 * formatting concepts, refer to the <a href="#summary">Summary</a>
 *
 * <p> Any characters not explicitly defined as conversions, date/time
 * conversion suffixes, or flags are illegal and are reserved for
 * future extensions.  Use of such a character in a format string will
 * cause an {@link UnknownFormatConversionException} or {@link
 * UnknownFormatFlagsException} to be thrown.
 *
 * <p> If the format specifier contains a width or precision with an invalid
 * value or which is otherwise unsupported, then a {@link
 * IllegalFormatWidthException} or {@link IllegalFormatPrecisionException}
 * respectively will be thrown.
 *
 * <p> If a format specifier contains a conversion character that is not
 * applicable to the corresponding argument, then an {@link
 * IllegalFormatConversionException} will be thrown.
 *
 * <p> All specified exceptions may be thrown by any of the {@code format}
 * methods of {@code Formatter} as well as by any {@code format} convenience
 * methods such as {@link String#format(String, Object...) String.format} and
 * {@link java.io.PrintStream#printf(String, Object...) PrintStream.printf}.
 *
 * <p> Conversions denoted by an upper-case character (i.e. {@code 'B'},
 * {@code 'H'}, {@code 'S'}, {@code 'C'}, {@code 'X'}, {@code 'E'},
 * {@code 'G'}, {@code 'A'}, and {@code 'T'}) are the same as those for the
 * corresponding lower-case conversion characters except that the result is
 * converted to upper case according to the rules of the prevailing {@link
 * java.util.Locale Locale}.  The result is equivalent to the following
 * invocation of {@link String#toUpperCase()}
 *
 * <pre>
 *    out.toUpperCase() </pre>
 *
 * <h4><a name="dgen">General</a></h4>
 *
 * <p> The following general conversions may be applied to any argument type:
 *
 * <table cellpadding=5 summary="dgConv">
 *
 * <tr><td valign="top"> {@code 'b'}
 * <td valign="top"> <tt>'&#92;u0062'</tt>
 * <td> Produces either "{@code true}" or "{@code false}" as returned by
 * {@link Boolean#toString(boolean)}.
 *
 * <p> If the argument is {@code null}, then the result is
 * "{@code false}".  If the argument is a {@code boolean} or {@link
 * Boolean}, then the result is the string returned by {@link
 * String#valueOf(boolean) String.valueOf()}.  Otherwise, the result is
 * "{@code true}".
 *
 * <p> If the {@code '#'} flag is given, then a {@link
 * FormatFlagsConversionMismatchException} will be thrown.
 *
 * <tr><td valign="top"> {@code 'B'}
 * <td valign="top"> <tt>'&#92;u0042'</tt>
 * <td> The upper-case variant of {@code 'b'}.
 *
 * <tr><td valign="top"> {@code 'h'}
 * <td valign="top"> <tt>'&#92;u0068'</tt>
 * <td> Produces a string representing the hash code value of the object.
 *
 * <p> If the argument, <i>arg</i> is {@code null}, then the
 * result is "{@code null}".  Otherwise, the result is obtained
 * by invoking {@code Integer.toHexString(arg.hashCode())}.
 *
 * <p> If the {@code '#'} flag is given, then a {@link
 * FormatFlagsConversionMismatchException} will be thrown.
 *
 * <tr><td valign="top"> {@code 'H'}
 * <td valign="top"> <tt>'&#92;u0048'</tt>
 * <td> The upper-case variant of {@code 'h'}.
 *
 * <tr><td valign="top"> {@code 's'}
 * <td valign="top"> <tt>'&#92;u0073'</tt>
 * <td> Produces a string.
 *
 * <p> If the argument is {@code null}, then the result is
 * "{@code null}".  If the argument implements {@link Formattable}, then
 * its {@link Formattable#formatTo formatTo} method is invoked.
 * Otherwise, the result is obtained by invoking the argument's
 * {@code toString()} method.
 *
 * <p> If the {@code '#'} flag is given and the argument is not a {@link
 * Formattable} , then a {@link FormatFlagsConversionMismatchException}
 * will be thrown.
 *
 * <tr><td valign="top"> {@code 'S'}
 * <td valign="top"> <tt>'&#92;u0053'</tt>
 * <td> The upper-case variant of {@code 's'}.
 *
 * </table>
 *
 * <p> The following <a name="dFlags">flags</a> apply to general conversions:
 *
 * <table cellpadding=5 summary="dFlags">
 *
 * <tr><td valign="top"> {@code '-'}
 * <td valign="top"> <tt>'&#92;u002d'</tt>
 * <td> Left justifies the output.  Spaces (<tt>'&#92;u0020'</tt>) will be
 * added at the end of the converted value as required to fill the minimum
 * width of the field.  If the width is not provided, then a {@link
 * MissingFormatWidthException} will be thrown.  If this flag is not given
 * then the output will be right-justified.
 *
 * <tr><td valign="top"> {@code '#'}
 * <td valign="top"> <tt>'&#92;u0023'</tt>
 * <td> Requires the output use an alternate form.  The definition of the
 * form is specified by the conversion.
 *
 * </table>
 *
 * <p> The <a name="genWidth">width</a> is the minimum number of characters to
 * be written to the
 * output.  If the length of the converted value is less than the width then
 * the output will be padded by <tt>'&nbsp;&nbsp;'</tt> (<tt>'&#92;u0020'</tt>)
 * until the total number of characters equals the width.  The padding is on
 * the left by default.  If the {@code '-'} flag is given, then the padding
 * will be on the right.  If the width is not specified then there is no
 * minimum.
 *
 * <p> The precision is the maximum number of characters to be written to the
 * output.  The precision is applied before the width, thus the output will be
 * truncated to {@code precision} characters even if the width is greater than
 * the precision.  If the precision is not specified then there is no explicit
 * limit on the number of characters.
 *
 * <h4><a name="dchar">Character</a></h4>
 *
 * This conversion may be applied to {@code char} and {@link Character}.  It
 * may also be applied to the types {@code byte}, {@link Byte},
 * {@code short}, and {@link Short}, {@code int} and {@link Integer} when
 * {@link Character#isValidCodePoint} returns {@code true}.  If it returns
 * {@code false} then an {@link IllegalFormatCodePointException} will be
 * thrown.
 *
 * <table cellpadding=5 summary="charConv">
 *
 * <tr><td valign="top"> {@code 'c'}
 * <td valign="top"> <tt>'&#92;u0063'</tt>
 * <td> Formats the argument as a Unicode character as described in <a
 * href="../lang/Character.html#unicode">Unicode Character
 * Representation</a>.  This may be more than one 16-bit {@code char} in
 * the case where the argument represents a supplementary character.
 *
 * <p> If the {@code '#'} flag is given, then a {@link
 * FormatFlagsConversionMismatchException} will be thrown.
 *
 * <tr><td valign="top"> {@code 'C'}
 * <td valign="top"> <tt>'&#92;u0043'</tt>
 * <td> The upper-case variant of {@code 'c'}.
 *
 * </table>
 *
 * <p> The {@code '-'} flag defined for <a href="#dFlags">General
 * conversions</a> applies.  If the {@code '#'} flag is given, then a {@link
 * FormatFlagsConversionMismatchException} will be thrown.
 *
 * <p> The width is defined as for <a href="#genWidth">General conversions</a>.
 *
 * <p> The precision is not applicable.  If the precision is specified then an
 * {@link IllegalFormatPrecisionException} will be thrown.
 *
 * <h4><a name="dnum">Numeric</a></h4>
 *
 * <p> Numeric conversions are divided into the following categories:
 *
 * <ol>
 *
 * <li> <a href="#dnint"><b>Byte, Short, Integer, and Long</b></a>
 *
 * <li> <a href="#dnbint"><b>BigInteger</b></a>
 *
 * <li> <a href="#dndec"><b>Float and Double</b></a>
 *
 * <li> <a href="#dnbdec"><b>BigDecimal</b></a>
 *
 * </ol>
 *
 * <p> Numeric types will be formatted according to the following algorithm:
 *
 * <p><b><a name="L10nAlgorithm"> Number Localization Algorithm</a></b>
 *
 * <p> After digits are obtained for the integer part, fractional part, and
 * exponent (as appropriate for the data type), the following transformation
 * is applied:
 *
 * <ol>
 *
 * <li> Each digit character <i>d</i> in the string is replaced by a
 * locale-specific digit computed relative to the current locale's
 * {@linkplain java.text.DecimalFormatSymbols#getZeroDigit() zero digit}
 * <i>z</i>; that is <i>d&nbsp;-&nbsp;</i> {@code '0'}
 * <i>&nbsp;+&nbsp;z</i>.
 *
 * <li> If a decimal separator is present, a locale-specific {@linkplain
 * java.text.DecimalFormatSymbols#getDecimalSeparator decimal separator} is
 * substituted.
 *
 * <li> If the {@code ','} (<tt>'&#92;u002c'</tt>)
 * <a name="L10nGroup">flag</a> is given, then the locale-specific {@linkplain
 * java.text.DecimalFormatSymbols#getGroupingSeparator grouping separator} is
 * inserted by scanning the integer part of the string from least significant
 * to most significant digits and inserting a separator at intervals defined by
 * the locale's {@linkplain java.text.DecimalFormat#getGroupingSize() grouping
 * size}.
 *
 * <li> If the {@code '0'} flag is given, then the locale-specific {@linkplain
 * java.text.DecimalFormatSymbols#getZeroDigit() zero digits} are inserted
 * after the sign character, if any, and before the first non-zero digit, until
 * the length of the string is equal to the requested field width.
 *
 * <li> If the value is negative and the {@code '('} flag is given, then a
 * {@code '('} (<tt>'&#92;u0028'</tt>) is prepended and a {@code ')'}
 * (<tt>'&#92;u0029'</tt>) is appended.
 *
 * <li> If the value is negative (or floating-point negative zero) and
 * {@code '('} flag is not given, then a {@code '-'} (<tt>'&#92;u002d'</tt>)
 * is prepended.
 *
 * <li> If the {@code '+'} flag is given and the value is positive or zero (or
 * floating-point positive zero), then a {@code '+'} (<tt>'&#92;u002b'</tt>)
 * will be prepended.
 *
 * </ol>
 *
 * <p> If the value is NaN or positive infinity the literal strings "NaN" or
 * "Infinity" respectively, will be output.  If the value is negative infinity,
 * then the output will be "(Infinity)" if the {@code '('} flag is given
 * otherwise the output will be "-Infinity".  These values are not localized.
 *
 * <p><a name="dnint"><b> Byte, Short, Integer, and Long </b></a>
 *
 * <p> The following conversions may be applied to {@code byte}, {@link Byte},
 * {@code short}, {@link Short}, {@code int} and {@link Integer},
 * {@code long}, and {@link Long}.
 *
 * <table cellpadding=5 summary="IntConv">
 *
 * <tr><td valign="top"> {@code 'd'}
 * <td valign="top"> <tt>'&#92;u0064'</tt>
 * <td> Formats the argument as a decimal integer. The <a
 * href="#L10nAlgorithm">localization algorithm</a> is applied.
 *
 * <p> If the {@code '0'} flag is given and the value is negative, then
 * the zero padding will occur after the sign.
 *
 * <p> If the {@code '#'} flag is given then a {@link
 * FormatFlagsConversionMismatchException} will be thrown.
 *
 * <tr><td valign="top"> {@code 'o'}
 * <td valign="top"> <tt>'&#92;u006f'</tt>
 * <td> Formats the argument as an integer in base eight.  No localization
 * is applied.
 *
 * <p> If <i>x</i> is negative then the result will be an unsigned value
 * generated by adding 2<sup>n</sup> to the value where {@code n} is the
 * number of bits in the type as returned by the static {@code SIZE} field
 * in the {@linkplain Byte#SIZE Byte}, {@linkplain Short#SIZE Short},
 * {@linkplain Integer#SIZE Integer}, or {@linkplain Long#SIZE Long}
 * classes as appropriate.
 *
 * <p> If the {@code '#'} flag is given then the output will always begin
 * with the radix indicator {@code '0'}.
 *
 * <p> If the {@code '0'} flag is given then the output will be padded
 * with leading zeros to the field width following any indication of sign.
 *
 * <p> If {@code '('}, {@code '+'}, '&nbsp;&nbsp;', or {@code ','} flags
 * are given then a {@link FormatFlagsConversionMismatchException} will be
 * thrown.
 *
 * <tr><td valign="top"> {@code 'x'}
 * <td valign="top"> <tt>'&#92;u0078'</tt>
 * <td> Formats the argument as an integer in base sixteen. No
 * localization is applied.
 *
 * <p> If <i>x</i> is negative then the result will be an unsigned value
 * generated by adding 2<sup>n</sup> to the value where {@code n} is the
 * number of bits in the type as returned by the static {@code SIZE} field
 * in the {@linkplain Byte#SIZE Byte}, {@linkplain Short#SIZE Short},
 * {@linkplain Integer#SIZE Integer}, or {@linkplain Long#SIZE Long}
 * classes as appropriate.
 *
 * <p> If the {@code '#'} flag is given then the output will always begin
 * with the radix indicator {@code "0x"}.
 *
 * <p> If the {@code '0'} flag is given then the output will be padded to
 * the field width with leading zeros after the radix indicator or sign (if
 * present).
 *
 * <p> If {@code '('}, <tt>'&nbsp;&nbsp;'</tt>, {@code '+'}, or
 * {@code ','} flags are given then a {@link
 * FormatFlagsConversionMismatchException} will be thrown.
 *
 * <tr><td valign="top"> {@code 'X'}
 * <td valign="top"> <tt>'&#92;u0058'</tt>
 * <td> The upper-case variant of {@code 'x'}.  The entire string
 * representing the number will be converted to {@linkplain
 * String#toUpperCase upper case} including the {@code 'x'} (if any) and
 * all hexadecimal digits {@code 'a'} - {@code 'f'}
 * (<tt>'&#92;u0061'</tt> -  <tt>'&#92;u0066'</tt>).
 *
 * </table>
 *
 * <p> If the conversion is {@code 'o'}, {@code 'x'}, or {@code 'X'} and
 * both the {@code '#'} and the {@code '0'} flags are given, then result will
 * contain the radix indicator ({@code '0'} for octal and {@code "0x"} or
 * {@code "0X"} for hexadecimal), some number of zeros (based on the width),
 * and the value.
 *
 * <p> If the {@code '-'} flag is not given, then the space padding will occur
 * before the sign.
 *
 * <p> The following <a name="intFlags">flags</a> apply to numeric integral
 * conversions:
 *
 * <table cellpadding=5 summary="intFlags">
 *
 * <tr><td valign="top"> {@code '+'}
 * <td valign="top"> <tt>'&#92;u002b'</tt>
 * <td> Requires the output to include a positive sign for all positive
 * numbers.  If this flag is not given then only negative values will
 * include a sign.
 *
 * <p> If both the {@code '+'} and <tt>'&nbsp;&nbsp;'</tt> flags are given
 * then an {@link IllegalFormatFlagsException} will be thrown.
 *
 * <tr><td valign="top"> <tt>'&nbsp;&nbsp;'</tt>
 * <td valign="top"> <tt>'&#92;u0020'</tt>
 * <td> Requires the output to include a single extra space
 * (<tt>'&#92;u0020'</tt>) for non-negative values.
 *
 * <p> If both the {@code '+'} and <tt>'&nbsp;&nbsp;'</tt> flags are given
 * then an {@link IllegalFormatFlagsException} will be thrown.
 *
 * <tr><td valign="top"> {@code '0'}
 * <td valign="top"> <tt>'&#92;u0030'</tt>
 * <td> Requires the output to be padded with leading {@linkplain
 * java.text.DecimalFormatSymbols#getZeroDigit zeros} to the minimum field
 * width following any sign or radix indicator except when converting NaN
 * or infinity.  If the width is not provided, then a {@link
 * MissingFormatWidthException} will be thrown.
 *
 * <p> If both the {@code '-'} and {@code '0'} flags are given then an
 * {@link IllegalFormatFlagsException} will be thrown.
 *
 * <tr><td valign="top"> {@code ','}
 * <td valign="top"> <tt>'&#92;u002c'</tt>
 * <td> Requires the output to include the locale-specific {@linkplain
 * java.text.DecimalFormatSymbols#getGroupingSeparator group separators} as
 * described in the <a href="#L10nGroup">"group" section</a> of the
 * localization algorithm.
 *
 * <tr><td valign="top"> {@code '('}
 * <td valign="top"> <tt>'&#92;u0028'</tt>
 * <td> Requires the output to prepend a {@code '('}
 * (<tt>'&#92;u0028'</tt>) and append a {@code ')'}
 * (<tt>'&#92;u0029'</tt>) to negative values.
 *
 * </table>
 *
 * <p> If no <a name="intdFlags">flags</a> are given the default formatting is
 * as follows:
 *
 * <ul>
 *
 * <li> The output is right-justified within the {@code width}
 *
 * <li> Negative numbers begin with a {@code '-'} (<tt>'&#92;u002d'</tt>)
 *
 * <li> Positive numbers and zero do not include a sign or extra leading
 * space
 *
 * <li> No grouping separators are included
 *
 * </ul>
 *
 * <p> The <a name="intWidth">width</a> is the minimum number of characters to
 * be written to the output.  This includes any signs, digits, grouping
 * separators, radix indicator, and parentheses.  If the length of the
 * converted value is less than the width then the output will be padded by
 * spaces (<tt>'&#92;u0020'</tt>) until the total number of characters equals
 * width.  The padding is on the left by default.  If {@code '-'} flag is
 * given then the padding will be on the right.  If width is not specified then
 * there is no minimum.
 *
 * <p> The precision is not applicable.  If precision is specified then an
 * {@link IllegalFormatPrecisionException} will be thrown.
 *
 * <p><a name="dnbint"><b> BigInteger </b></a>
 *
 * <p> The following conversions may be applied to {@link
 * java.math.BigInteger}.
 *
 * <table cellpadding=5 summary="BIntConv">
 *
 * <tr><td valign="top"> {@code 'd'}
 * <td valign="top"> <tt>'&#92;u0064'</tt>
 * <td> Requires the output to be formatted as a decimal integer. The <a
 * href="#L10nAlgorithm">localization algorithm</a> is applied.
 *
 * <p> If the {@code '#'} flag is given {@link
 * FormatFlagsConversionMismatchException} will be thrown.
 *
 * <tr><td valign="top"> {@code 'o'}
 * <td valign="top"> <tt>'&#92;u006f'</tt>
 * <td> Requires the output to be formatted as an integer in base eight.
 * No localization is applied.
 *
 * <p> If <i>x</i> is negative then the result will be a signed value
 * beginning with {@code '-'} (<tt>'&#92;u002d'</tt>).  Signed output is
 * allowed for this type because unlike the primitive types it is not
 * possible to create an unsigned equivalent without assuming an explicit
 * data-type size.
 *
 * <p> If <i>x</i> is positive or zero and the {@code '+'} flag is given
 * then the result will begin with {@code '+'} (<tt>'&#92;u002b'</tt>).
 *
 * <p> If the {@code '#'} flag is given then the output will always begin
 * with {@code '0'} prefix.
 *
 * <p> If the {@code '0'} flag is given then the output will be padded
 * with leading zeros to the field width following any indication of sign.
 *
 * <p> If the {@code ','} flag is given then a {@link
 * FormatFlagsConversionMismatchException} will be thrown.
 *
 * <tr><td valign="top"> {@code 'x'}
 * <td valign="top"> <tt>'&#92;u0078'</tt>
 * <td> Requires the output to be formatted as an integer in base
 * sixteen.  No localization is applied.
 *
 * <p> If <i>x</i> is negative then the result will be a signed value
 * beginning with {@code '-'} (<tt>'&#92;u002d'</tt>).  Signed output is
 * allowed for this type because unlike the primitive types it is not
 * possible to create an unsigned equivalent without assuming an explicit
 * data-type size.
 *
 * <p> If <i>x</i> is positive or zero and the {@code '+'} flag is given
 * then the result will begin with {@code '+'} (<tt>'&#92;u002b'</tt>).
 *
 * <p> If the {@code '#'} flag is given then the output will always begin
 * with the radix indicator {@code "0x"}.
 *
 * <p> If the {@code '0'} flag is given then the output will be padded to
 * the field width with leading zeros after the radix indicator or sign (if
 * present).
 *
 * <p> If the {@code ','} flag is given then a {@link
 * FormatFlagsConversionMismatchException} will be thrown.
 *
 * <tr><td valign="top"> {@code 'X'}
 * <td valign="top"> <tt>'&#92;u0058'</tt>
 * <td> The upper-case variant of {@code 'x'}.  The entire string
 * representing the number will be converted to {@linkplain
 * String#toUpperCase upper case} including the {@code 'x'} (if any) and
 * all hexadecimal digits {@code 'a'} - {@code 'f'}
 * (<tt>'&#92;u0061'</tt> - <tt>'&#92;u0066'</tt>).
 *
 * </table>
 *
 * <p> If the conversion is {@code 'o'}, {@code 'x'}, or {@code 'X'} and
 * both the {@code '#'} and the {@code '0'} flags are given, then result will
 * contain the base indicator ({@code '0'} for octal and {@code "0x"} or
 * {@code "0X"} for hexadecimal), some number of zeros (based on the width),
 * and the value.
 *
 * <p> If the {@code '0'} flag is given and the value is negative, then the
 * zero padding will occur after the sign.
 *
 * <p> If the {@code '-'} flag is not given, then the space padding will occur
 * before the sign.
 *
 * <p> All <a href="#intFlags">flags</a> defined for Byte, Short, Integer, and
 * Long apply.  The <a href="#intdFlags">default behavior</a> when no flags are
 * given is the same as for Byte, Short, Integer, and Long.
 *
 * <p> The specification of <a href="#intWidth">width</a> is the same as
 * defined for Byte, Short, Integer, and Long.
 *
 * <p> The precision is not applicable.  If precision is specified then an
 * {@link IllegalFormatPrecisionException} will be thrown.
 *
 * <p><a name="dndec"><b> Float and Double</b></a>
 *
 * <p> The following conversions may be applied to {@code float}, {@link
 * Float}, {@code double} and {@link Double}.
 *
 * <table cellpadding=5 summary="floatConv">
 *
 * <tr><td valign="top"> {@code 'e'}
 * <td valign="top"> <tt>'&#92;u0065'</tt>
 * <td> Requires the output to be formatted using <a
 * name="scientific">computerized scientific notation</a>.  The <a
 * href="#L10nAlgorithm">localization algorithm</a> is applied.
 *
 * <p> The formatting of the magnitude <i>m</i> depends upon its value.
 *
 * <p> If <i>m</i> is NaN or infinite, the literal strings "NaN" or
 * "Infinity", respectively, will be output.  These values are not
 * localized.
 *
 * <p> If <i>m</i> is positive-zero or negative-zero, then the exponent
 * will be {@code "+00"}.
 *
 * <p> Otherwise, the result is a string that represents the sign and
 * magnitude (absolute value) of the argument.  The formatting of the sign
 * is described in the <a href="#L10nAlgorithm">localization
 * algorithm</a>. The formatting of the magnitude <i>m</i> depends upon its
 * value.
 *
 * <p> Let <i>n</i> be the unique integer such that 10<sup><i>n</i></sup>
 * &lt;= <i>m</i> &lt; 10<sup><i>n</i>+1</sup>; then let <i>a</i> be the
 * mathematically exact quotient of <i>m</i> and 10<sup><i>n</i></sup> so
 * that 1 &lt;= <i>a</i> &lt; 10. The magnitude is then represented as the
 * integer part of <i>a</i>, as a single decimal digit, followed by the
 * decimal separator followed by decimal digits representing the fractional
 * part of <i>a</i>, followed by the exponent symbol {@code 'e'}
 * (<tt>'&#92;u0065'</tt>), followed by the sign of the exponent, followed
 * by a representation of <i>n</i> as a decimal integer, as produced by the
 * method {@link Long#toString(long, int)}, and zero-padded to include at
 * least two digits.
 *
 * <p> The number of digits in the result for the fractional part of
 * <i>m</i> or <i>a</i> is equal to the precision.  If the precision is not
 * specified then the default value is {@code 6}. If the precision is less
 * than the number of digits which would appear after the decimal point in
 * the string returned by {@link Float#toString(float)} or {@link
 * Double#toString(double)} respectively, then the value will be rounded
 * using the {@linkplain java.math.BigDecimal#ROUND_HALF_UP round half up
 * algorithm}.  Otherwise, zeros may be appended to reach the precision.
 * For a canonical representation of the value, use {@link
 * Float#toString(float)} or {@link Double#toString(double)} as
 * appropriate.
 *
 * <p>If the {@code ','} flag is given, then an {@link
 * FormatFlagsConversionMismatchException} will be thrown.
 *
 * <tr><td valign="top"> {@code 'E'}
 * <td valign="top"> <tt>'&#92;u0045'</tt>
 * <td> The upper-case variant of {@code 'e'}.  The exponent symbol
 * will be {@code 'E'} (<tt>'&#92;u0045'</tt>).
 *
 * <tr><td valign="top"> {@code 'g'}
 * <td valign="top"> <tt>'&#92;u0067'</tt>
 * <td> Requires the output to be formatted in general scientific notation
 * as described below. The <a href="#L10nAlgorithm">localization
 * algorithm</a> is applied.
 *
 * <p> After rounding for the precision, the formatting of the resulting
 * magnitude <i>m</i> depends on its value.
 *
 * <p> If <i>m</i> is greater than or equal to 10<sup>-4</sup> but less
 * than 10<sup>precision</sup> then it is represented in <i><a
 * href="#decimal">decimal format</a></i>.
 *
 * <p> If <i>m</i> is less than 10<sup>-4</sup> or greater than or equal to
 * 10<sup>precision</sup>, then it is represented in <i><a
 * href="#scientific">computerized scientific notation</a></i>.
 *
 * <p> The total number of significant digits in <i>m</i> is equal to the
 * precision.  If the precision is not specified, then the default value is
 * {@code 6}.  If the precision is {@code 0}, then it is taken to be
 * {@code 1}.
 *
 * <p> If the {@code '#'} flag is given then an {@link
 * FormatFlagsConversionMismatchException} will be thrown.
 *
 * <tr><td valign="top"> {@code 'G'}
 * <td valign="top"> <tt>'&#92;u0047'</tt>
 * <td> The upper-case variant of {@code 'g'}.
 *
 * <tr><td valign="top"> {@code 'f'}
 * <td valign="top"> <tt>'&#92;u0066'</tt>
 * <td> Requires the output to be formatted using <a name="decimal">decimal
 * format</a>.  The <a href="#L10nAlgorithm">localization algorithm</a> is
 * applied.
 *
 * <p> The result is a string that represents the sign and magnitude
 * (absolute value) of the argument.  The formatting of the sign is
 * described in the <a href="#L10nAlgorithm">localization
 * algorithm</a>. The formatting of the magnitude <i>m</i> depends upon its
 * value.
 *
 * <p> If <i>m</i> NaN or infinite, the literal strings "NaN" or
 * "Infinity", respectively, will be output.  These values are not
 * localized.
 *
 * <p> The magnitude is formatted as the integer part of <i>m</i>, with no
 * leading zeroes, followed by the decimal separator followed by one or
 * more decimal digits representing the fractional part of <i>m</i>.
 *
 * <p> The number of digits in the result for the fractional part of
 * <i>m</i> or <i>a</i> is equal to the precision.  If the precision is not
 * specified then the default value is {@code 6}. If the precision is less
 * than the number of digits which would appear after the decimal point in
 * the string returned by {@link Float#toString(float)} or {@link
 * Double#toString(double)} respectively, then the value will be rounded
 * using the {@linkplain java.math.BigDecimal#ROUND_HALF_UP round half up
 * algorithm}.  Otherwise, zeros may be appended to reach the precision.
 * For a canonical representation of the value, use {@link
 * Float#toString(float)} or {@link Double#toString(double)} as
 * appropriate.
 *
 * <tr><td valign="top"> {@code 'a'}
 * <td valign="top"> <tt>'&#92;u0061'</tt>
 * <td> Requires the output to be formatted in hexadecimal exponential
 * form.  No localization is applied.
 *
 * <p> The result is a string that represents the sign and magnitude
 * (absolute value) of the argument <i>x</i>.
 *
 * <p> If <i>x</i> is negative or a negative-zero value then the result
 * will begin with {@code '-'} (<tt>'&#92;u002d'</tt>).
 *
 * <p> If <i>x</i> is positive or a positive-zero value and the
 * {@code '+'} flag is given then the result will begin with {@code '+'}
 * (<tt>'&#92;u002b'</tt>).
 *
 * <p> The formatting of the magnitude <i>m</i> depends upon its value.
 *
 * <ul>
 *
 * <li> If the value is NaN or infinite, the literal strings "NaN" or
 * "Infinity", respectively, will be output.
 *
 * <li> If <i>m</i> is zero then it is represented by the string
 * {@code "0x0.0p0"}.
 *
 * <li> If <i>m</i> is a {@code double} value with a normalized
 * representation then substrings are used to represent the significand and
 * exponent fields.  The significand is represented by the characters
 * {@code "0x1."} followed by the hexadecimal representation of the rest
 * of the significand as a fraction.  The exponent is represented by
 * {@code 'p'} (<tt>'&#92;u0070'</tt>) followed by a decimal string of the
 * unbiased exponent as if produced by invoking {@link
 * Integer#toString(int) Integer.toString} on the exponent value.  If the
 * precision is specified, the value is rounded to the given number of
 * hexadecimal digits.
 *
 * <li> If <i>m</i> is a {@code double} value with a subnormal
 * representation then, unless the precision is specified to be in the range
 * 1 through 12, inclusive, the significand is represented by the characters
 * {@code '0x0.'} followed by the hexadecimal representation of the rest of
 * the significand as a fraction, and the exponent represented by
 * {@code 'p-1022'}.  If the precision is in the interval
 * [1,&nbsp;12], the subnormal value is normalized such that it
 * begins with the characters {@code '0x1.'}, rounded to the number of
 * hexadecimal digits of precision, and the exponent adjusted
 * accordingly.  Note that there must be at least one nonzero digit in a
 * subnormal significand.
 *
 * </ul>
 *
 * <p> If the {@code '('} or {@code ','} flags are given, then a {@link
 * FormatFlagsConversionMismatchException} will be thrown.
 *
 * <tr><td valign="top"> {@code 'A'}
 * <td valign="top"> <tt>'&#92;u0041'</tt>
 * <td> The upper-case variant of {@code 'a'}.  The entire string
 * representing the number will be converted to upper case including the
 * {@code 'x'} (<tt>'&#92;u0078'</tt>) and {@code 'p'}
 * (<tt>'&#92;u0070'</tt> and all hexadecimal digits {@code 'a'} -
 * {@code 'f'} (<tt>'&#92;u0061'</tt> - <tt>'&#92;u0066'</tt>).
 *
 * </table>
 *
 * <p> All <a href="#intFlags">flags</a> defined for Byte, Short, Integer, and
 * Long apply.
 *
 * <p> If the {@code '#'} flag is given, then the decimal separator will
 * always be present.
 *
 * <p> If no <a name="floatdFlags">flags</a> are given the default formatting
 * is as follows:
 *
 * <ul>
 *
 * <li> The output is right-justified within the {@code width}
 *
 * <li> Negative numbers begin with a {@code '-'}
 *
 * <li> Positive numbers and positive zero do not include a sign or extra
 * leading space
 *
 * <li> No grouping separators are included
 *
 * <li> The decimal separator will only appear if a digit follows it
 *
 * </ul>
 *
 * <p> The <a name="floatDWidth">width</a> is the minimum number of characters
 * to be written to the output.  This includes any signs, digits, grouping
 * separators, decimal separators, exponential symbol, radix indicator,
 * parentheses, and strings representing infinity and NaN as applicable.  If
 * the length of the converted value is less than the width then the output
 * will be padded by spaces (<tt>'&#92;u0020'</tt>) until the total number of
 * characters equals width.  The padding is on the left by default.  If the
 * {@code '-'} flag is given then the padding will be on the right.  If width
 * is not specified then there is no minimum.
 *
 * <p> If the <a name="floatDPrec">conversion</a> is {@code 'e'},
 * {@code 'E'} or {@code 'f'}, then the precision is the number of digits
 * after the decimal separator.  If the precision is not specified, then it is
 * assumed to be {@code 6}.
 *
 * <p> If the conversion is {@code 'g'} or {@code 'G'}, then the precision is
 * the total number of significant digits in the resulting magnitude after
 * rounding.  If the precision is not specified, then the default value is
 * {@code 6}.  If the precision is {@code 0}, then it is taken to be
 * {@code 1}.
 *
 * <p> If the conversion is {@code 'a'} or {@code 'A'}, then the precision
 * is the number of hexadecimal digits after the radix point.  If the
 * precision is not provided, then all of the digits as returned by {@link
 * Double#toHexString(double)} will be output.
 *
 * <p><a name="dnbdec"><b> BigDecimal </b></a>
 *
 * <p> The following conversions may be applied {@link java.math.BigDecimal
 * BigDecimal}.
 *
 * <table cellpadding=5 summary="floatConv">
 *
 * <tr><td valign="top"> {@code 'e'}
 * <td valign="top"> <tt>'&#92;u0065'</tt>
 * <td> Requires the output to be formatted using <a
 * name="bscientific">computerized scientific notation</a>.  The <a
 * href="#L10nAlgorithm">localization algorithm</a> is applied.
 *
 * <p> The formatting of the magnitude <i>m</i> depends upon its value.
 *
 * <p> If <i>m</i> is positive-zero or negative-zero, then the exponent
 * will be {@code "+00"}.
 *
 * <p> Otherwise, the result is a string that represents the sign and
 * magnitude (absolute value) of the argument.  The formatting of the sign
 * is described in the <a href="#L10nAlgorithm">localization
 * algorithm</a>. The formatting of the magnitude <i>m</i> depends upon its
 * value.
 *
 * <p> Let <i>n</i> be the unique integer such that 10<sup><i>n</i></sup>
 * &lt;= <i>m</i> &lt; 10<sup><i>n</i>+1</sup>; then let <i>a</i> be the
 * mathematically exact quotient of <i>m</i> and 10<sup><i>n</i></sup> so
 * that 1 &lt;= <i>a</i> &lt; 10. The magnitude is then represented as the
 * integer part of <i>a</i>, as a single decimal digit, followed by the
 * decimal separator followed by decimal digits representing the fractional
 * part of <i>a</i>, followed by the exponent symbol {@code 'e'}
 * (<tt>'&#92;u0065'</tt>), followed by the sign of the exponent, followed
 * by a representation of <i>n</i> as a decimal integer, as produced by the
 * method {@link Long#toString(long, int)}, and zero-padded to include at
 * least two digits.
 *
 * <p> The number of digits in the result for the fractional part of
 * <i>m</i> or <i>a</i> is equal to the precision.  If the precision is not
 * specified then the default value is {@code 6}.  If the precision is
 * less than the number of digits to the right of the decimal point then
 * the value will be rounded using the
 * {@linkplain java.math.BigDecimal#ROUND_HALF_UP round half up
 * algorithm}.  Otherwise, zeros may be appended to reach the precision.
 * For a canonical representation of the value, use {@link
 * BigDecimal#toString()}.
 *
 * <p> If the {@code ','} flag is given, then an {@link
 * FormatFlagsConversionMismatchException} will be thrown.
 *
 * <tr><td valign="top"> {@code 'E'}
 * <td valign="top"> <tt>'&#92;u0045'</tt>
 * <td> The upper-case variant of {@code 'e'}.  The exponent symbol
 * will be {@code 'E'} (<tt>'&#92;u0045'</tt>).
 *
 * <tr><td valign="top"> {@code 'g'}
 * <td valign="top"> <tt>'&#92;u0067'</tt>
 * <td> Requires the output to be formatted in general scientific notation
 * as described below. The <a href="#L10nAlgorithm">localization
 * algorithm</a> is applied.
 *
 * <p> After rounding for the precision, the formatting of the resulting
 * magnitude <i>m</i> depends on its value.
 *
 * <p> If <i>m</i> is greater than or equal to 10<sup>-4</sup> but less
 * than 10<sup>precision</sup> then it is represented in <i><a
 * href="#bdecimal">decimal format</a></i>.
 *
 * <p> If <i>m</i> is less than 10<sup>-4</sup> or greater than or equal to
 * 10<sup>precision</sup>, then it is represented in <i><a
 * href="#bscientific">computerized scientific notation</a></i>.
 *
 * <p> The total number of significant digits in <i>m</i> is equal to the
 * precision.  If the precision is not specified, then the default value is
 * {@code 6}.  If the precision is {@code 0}, then it is taken to be
 * {@code 1}.
 *
 * <p> If the {@code '#'} flag is given then an {@link
 * FormatFlagsConversionMismatchException} will be thrown.
 *
 * <tr><td valign="top"> {@code 'G'}
 * <td valign="top"> <tt>'&#92;u0047'</tt>
 * <td> The upper-case variant of {@code 'g'}.
 *
 * <tr><td valign="top"> {@code 'f'}
 * <td valign="top"> <tt>'&#92;u0066'</tt>
 * <td> Requires the output to be formatted using <a name="bdecimal">decimal
 * format</a>.  The <a href="#L10nAlgorithm">localization algorithm</a> is
 * applied.
 *
 * <p> The result is a string that represents the sign and magnitude
 * (absolute value) of the argument.  The formatting of the sign is
 * described in the <a href="#L10nAlgorithm">localization
 * algorithm</a>. The formatting of the magnitude <i>m</i> depends upon its
 * value.
 *
 * <p> The magnitude is formatted as the integer part of <i>m</i>, with no
 * leading zeroes, followed by the decimal separator followed by one or
 * more decimal digits representing the fractional part of <i>m</i>.
 *
 * <p> The number of digits in the result for the fractional part of
 * <i>m</i> or <i>a</i> is equal to the precision. If the precision is not
 * specified then the default value is {@code 6}.  If the precision is
 * less than the number of digits to the right of the decimal point
 * then the value will be rounded using the
 * {@linkplain java.math.BigDecimal#ROUND_HALF_UP round half up
 * algorithm}.  Otherwise, zeros may be appended to reach the precision.
 * For a canonical representation of the value, use {@link
 * BigDecimal#toString()}.
 *
 * </table>
 *
 * <p> All <a href="#intFlags">flags</a> defined for Byte, Short, Integer, and
 * Long apply.
 *
 * <p> If the {@code '#'} flag is given, then the decimal separator will
 * always be present.
 *
 * <p> The <a href="#floatdFlags">default behavior</a> when no flags are
 * given is the same as for Float and Double.
 *
 * <p> The specification of <a href="#floatDWidth">width</a> and <a
 * href="#floatDPrec">precision</a> is the same as defined for Float and
 * Double.
 *
 * <h4><a name="ddt">Date/Time</a></h4>
 *
 * <p> This conversion may be applied to {@code long}, {@link Long}, {@link
 * Calendar}, {@link Date} and {@link TemporalAccessor TemporalAccessor}
 *
 * <table cellpadding=5 summary="DTConv">
 *
 * <tr><td valign="top"> {@code 't'}
 * <td valign="top"> <tt>'&#92;u0074'</tt>
 * <td> Prefix for date and time conversion characters.
 * <tr><td valign="top"> {@code 'T'}
 * <td valign="top"> <tt>'&#92;u0054'</tt>
 * <td> The upper-case variant of {@code 't'}.
 *
 * </table>
 *
 * <p> The following date and time conversion character suffixes are defined
 * for the {@code 't'} and {@code 'T'} conversions.  The types are similar to
 * but not completely identical to those defined by GNU {@code date} and
 * POSIX {@code strftime(3c)}.  Additional conversion types are provided to
 * access Java-specific functionality (e.g. {@code 'L'} for milliseconds
 * within the second).
 *
 * <p> The following conversion characters are used for formatting times:
 *
 * <table cellpadding=5 summary="time">
 *
 * <tr><td valign="top"> {@code 'H'}
 * <td valign="top"> <tt>'&#92;u0048'</tt>
 * <td> Hour of the day for the 24-hour clock, formatted as two digits with
 * a leading zero as necessary i.e. {@code 00 - 23}. {@code 00}
 * corresponds to midnight.
 *
 * <tr><td valign="top">{@code 'I'}
 * <td valign="top"> <tt>'&#92;u0049'</tt>
 * <td> Hour for the 12-hour clock, formatted as two digits with a leading
 * zero as necessary, i.e.  {@code 01 - 12}.  {@code 01} corresponds to
 * one o'clock (either morning or afternoon).
 *
 * <tr><td valign="top">{@code 'k'}
 * <td valign="top"> <tt>'&#92;u006b'</tt>
 * <td> Hour of the day for the 24-hour clock, i.e. {@code 0 - 23}.
 * {@code 0} corresponds to midnight.
 *
 * <tr><td valign="top">{@code 'l'}
 * <td valign="top"> <tt>'&#92;u006c'</tt>
 * <td> Hour for the 12-hour clock, i.e. {@code 1 - 12}.  {@code 1}
 * corresponds to one o'clock (either morning or afternoon).
 *
 * <tr><td valign="top">{@code 'M'}
 * <td valign="top"> <tt>'&#92;u004d'</tt>
 * <td> Minute within the hour formatted as two digits with a leading zero
 * as necessary, i.e.  {@code 00 - 59}.
 *
 * <tr><td valign="top">{@code 'S'}
 * <td valign="top"> <tt>'&#92;u0053'</tt>
 * <td> Seconds within the minute, formatted as two digits with a leading
 * zero as necessary, i.e. {@code 00 - 60} ("{@code 60}" is a special
 * value required to support leap seconds).
 *
 * <tr><td valign="top">{@code 'L'}
 * <td valign="top"> <tt>'&#92;u004c'</tt>
 * <td> Millisecond within the second formatted as three digits with
 * leading zeros as necessary, i.e. {@code 000 - 999}.
 *
 * <tr><td valign="top">{@code 'N'}
 * <td valign="top"> <tt>'&#92;u004e'</tt>
 * <td> Nanosecond within the second, formatted as nine digits with leading
 * zeros as necessary, i.e. {@code 000000000 - 999999999}.  The precision
 * of this value is limited by the resolution of the underlying operating
 * system or hardware.
 *
 * <tr><td valign="top">{@code 'p'}
 * <td valign="top"> <tt>'&#92;u0070'</tt>
 * <td> Locale-specific {@linkplain
 * java.text.DateFormatSymbols#getAmPmStrings morning or afternoon} marker
 * in lower case, e.g."{@code am}" or "{@code pm}".  Use of the
 * conversion prefix {@code 'T'} forces this output to upper case.  (Note
 * that {@code 'p'} produces lower-case output.  This is different from
 * GNU {@code date} and POSIX {@code strftime(3c)} which produce
 * upper-case output.)
 *
 * <tr><td valign="top">{@code 'z'}
 * <td valign="top"> <tt>'&#92;u007a'</tt>
 * <td> <a href="http://www.ietf.org/rfc/rfc0822.txt">RFC&nbsp;822</a>
 * style numeric time zone offset from GMT, e.g. {@code -0800}.  This
 * value will be adjusted as necessary for Daylight Saving Time.  For
 * {@code long}, {@link Long}, and {@link Date} the time zone used is
 * the {@linkplain TimeZone#getDefault() default time zone} for this
 * instance of the Java virtual machine.
 *
 * <tr><td valign="top">{@code 'Z'}
 * <td valign="top"> <tt>'&#92;u005a'</tt>
 * <td> A string representing the abbreviation for the time zone.  This
 * value will be adjusted as necessary for Daylight Saving Time.  For
 * {@code long}, {@link Long}, and {@link Date} the time zone used is
 * the {@linkplain TimeZone#getDefault() default time zone} for this
 * instance of the Java virtual machine.  The Formatter's locale will
 * supersede the locale of the argument (if any).
 *
 * <tr><td valign="top">{@code 's'}
 * <td valign="top"> <tt>'&#92;u0073'</tt>
 * <td> Seconds since the beginning of the epoch starting at 1 January 1970
 * {@code 00:00:00} UTC, i.e. {@code Long.MIN_VALUE/1000} to
 * {@code Long.MAX_VALUE/1000}.
 *
 * <tr><td valign="top">{@code 'Q'}
 * <td valign="top"> <tt>'&#92;u004f'</tt>
 * <td> Milliseconds since the beginning of the epoch starting at 1 January
 * 1970 {@code 00:00:00} UTC, i.e. {@code Long.MIN_VALUE} to
 * {@code Long.MAX_VALUE}. The precision of this value is limited by
 * the resolution of the underlying operating system or hardware.
 *
 * </table>
 *
 * <p> The following conversion characters are used for formatting dates:
 *
 * <table cellpadding=5 summary="date">
 *
 * <tr><td valign="top">{@code 'B'}
 * <td valign="top"> <tt>'&#92;u0042'</tt>
 * <td> Locale-specific {@linkplain java.text.DateFormatSymbols#getMonths
 * full month name}, e.g. {@code "January"}, {@code "February"}.
 *
 * <tr><td valign="top">{@code 'b'}
 * <td valign="top"> <tt>'&#92;u0062'</tt>
 * <td> Locale-specific {@linkplain
 * java.text.DateFormatSymbols#getShortMonths abbreviated month name},
 * e.g. {@code "Jan"}, {@code "Feb"}.
 *
 * <tr><td valign="top">{@code 'h'}
 * <td valign="top"> <tt>'&#92;u0068'</tt>
 * <td> Same as {@code 'b'}.
 *
 * <tr><td valign="top">{@code 'A'}
 * <td valign="top"> <tt>'&#92;u0041'</tt>
 * <td> Locale-specific full name of the {@linkplain
 * java.text.DateFormatSymbols#getWeekdays day of the week},
 * e.g. {@code "Sunday"}, {@code "Monday"}
 *
 * <tr><td valign="top">{@code 'a'}
 * <td valign="top"> <tt>'&#92;u0061'</tt>
 * <td> Locale-specific short name of the {@linkplain
 * java.text.DateFormatSymbols#getShortWeekdays day of the week},
 * e.g. {@code "Sun"}, {@code "Mon"}
 *
 * <tr><td valign="top">{@code 'C'}
 * <td valign="top"> <tt>'&#92;u0043'</tt>
 * <td> Four-digit year divided by {@code 100}, formatted as two digits
 * with leading zero as necessary, i.e. {@code 00 - 99}
 *
 * <tr><td valign="top">{@code 'Y'}
 * <td valign="top"> <tt>'&#92;u0059'</tt> <td> Year, formatted to at least
 * four digits with leading zeros as necessary, e.g. {@code 0092} equals
 * {@code 92} CE for the Gregorian calendar.
 *
 * <tr><td valign="top">{@code 'y'}
 * <td valign="top"> <tt>'&#92;u0079'</tt>
 * <td> Last two digits of the year, formatted with leading zeros as
 * necessary, i.e. {@code 00 - 99}.
 *
 * <tr><td valign="top">{@code 'j'}
 * <td valign="top"> <tt>'&#92;u006a'</tt>
 * <td> Day of year, formatted as three digits with leading zeros as
 * necessary, e.g. {@code 001 - 366} for the Gregorian calendar.
 * {@code 001} corresponds to the first day of the year.
 *
 * <tr><td valign="top">{@code 'm'}
 * <td valign="top"> <tt>'&#92;u006d'</tt>
 * <td> Month, formatted as two digits with leading zeros as necessary,
 * i.e. {@code 01 - 13}, where "{@code 01}" is the first month of the
 * year and ("{@code 13}" is a special value required to support lunar
 * calendars).
 *
 * <tr><td valign="top">{@code 'd'}
 * <td valign="top"> <tt>'&#92;u0064'</tt>
 * <td> Day of month, formatted as two digits with leading zeros as
 * necessary, i.e. {@code 01 - 31}, where "{@code 01}" is the first day
 * of the month.
 *
 * <tr><td valign="top">{@code 'e'}
 * <td valign="top"> <tt>'&#92;u0065'</tt>
 * <td> Day of month, formatted as two digits, i.e. {@code 1 - 31} where
 * "{@code 1}" is the first day of the month.
 *
 * </table>
 *
 * <p> The following conversion characters are used for formatting common
 * date/time compositions.
 *
 * <table cellpadding=5 summary="composites">
 *
 * <tr><td valign="top">{@code 'R'}
 * <td valign="top"> <tt>'&#92;u0052'</tt>
 * <td> Time formatted for the 24-hour clock as {@code "%tH:%tM"}
 *
 * <tr><td valign="top">{@code 'T'}
 * <td valign="top"> <tt>'&#92;u0054'</tt>
 * <td> Time formatted for the 24-hour clock as {@code "%tH:%tM:%tS"}.
 *
 * <tr><td valign="top">{@code 'r'}
 * <td valign="top"> <tt>'&#92;u0072'</tt>
 * <td> Time formatted for the 12-hour clock as {@code "%tI:%tM:%tS
 * %Tp"}.  The location of the morning or afternoon marker
 * ({@code '%Tp'}) may be locale-dependent.
 *
 * <tr><td valign="top">{@code 'D'}
 * <td valign="top"> <tt>'&#92;u0044'</tt>
 * <td> Date formatted as {@code "%tm/%td/%ty"}.
 *
 * <tr><td valign="top">{@code 'F'}
 * <td valign="top"> <tt>'&#92;u0046'</tt>
 * <td> <a href="http://www.w3.org/TR/NOTE-datetime">ISO&nbsp;8601</a>
 * complete date formatted as {@code "%tY-%tm-%td"}.
 *
 * <tr><td valign="top">{@code 'c'}
 * <td valign="top"> <tt>'&#92;u0063'</tt>
 * <td> Date and time formatted as {@code "%ta %tb %td %tT %tZ %tY"},
 * e.g. {@code "Sun Jul 20 16:17:00 EDT 1969"}.
 *
 * </table>
 *
 * <p> The {@code '-'} flag defined for <a href="#dFlags">General
 * conversions</a> applies.  If the {@code '#'} flag is given, then a {@link
 * FormatFlagsConversionMismatchException} will be thrown.
 *
 * <p> The width is the minimum number of characters to
 * be written to the output.  If the length of the converted value is less than
 * the {@code width} then the output will be padded by spaces
 * (<tt>'&#92;u0020'</tt>) until the total number of characters equals width.
 * The padding is on the left by default.  If the {@code '-'} flag is given
 * then the padding will be on the right.  If width is not specified then there
 * is no minimum.
 *
 * <p> The precision is not applicable.  If the precision is specified then an
 * {@link IllegalFormatPrecisionException} will be thrown.
 *
 * <h4><a name="dper">Percent</a></h4>
 *
 * <p> The conversion does not correspond to any argument.
 *
 * <table cellpadding=5 summary="DTConv">
 *
 * <tr><td valign="top">{@code '%'}
 * <td> The result is a literal {@code '%'} (<tt>'&#92;u0025'</tt>)
 *
 * <p> The width is the minimum number of characters to
 * be written to the output including the {@code '%'}.  If the length of the
 * converted value is less than the {@code width} then the output will be
 * padded by spaces (<tt>'&#92;u0020'</tt>) until the total number of
 * characters equals width.  The padding is on the left.  If width is not
 * specified then just the {@code '%'} is output.
 *
 * <p> The {@code '-'} flag defined for <a href="#dFlags">General
 * conversions</a> applies.  If any other flags are provided, then a
 * {@link FormatFlagsConversionMismatchException} will be thrown.
 *
 * <p> The precision is not applicable.  If the precision is specified an
 * {@link IllegalFormatPrecisionException} will be thrown.
 *
 * </table>
 *
 * <h4><a name="dls">Line Separator</a></h4>
 *
 * <p> The conversion does not correspond to any argument.
 *
 * <table cellpadding=5 summary="DTConv">
 *
 * <tr><td valign="top">{@code 'n'}
 * <td> the platform-specific line separator as returned by {@link
 * System#getProperty System.getProperty("line.separator")}.
 *
 * </table>
 *
 * <p> Flags, width, and precision are not applicable.  If any are provided an
 * {@link IllegalFormatFlagsException}, {@link IllegalFormatWidthException},
 * and {@link IllegalFormatPrecisionException}, respectively will be thrown.
 *
 * <h4><a name="dpos">Argument Index</a></h4>
 *
 * <p> Format specifiers can reference arguments in three ways:
 *
 * <ul>
 *
 * <li> <i>Explicit indexing</i> is used when the format specifier contains an
 * argument index.  The argument index is a decimal integer indicating the
 * position of the argument in the argument list.  The first argument is
 * referenced by "{@code 1$}", the second by "{@code 2$}", etc.  An argument
 * may be referenced more than once.
 *
 * <p> For example:
 *
 * <blockquote><pre>
 *   formatter.format("%4$s %3$s %2$s %1$s %4$s %3$s %2$s %1$s",
 *                    "a", "b", "c", "d")
 *   // -&gt; "d c b a d c b a"
 * </pre></blockquote>
 *
 * <li> <i>Relative indexing</i> is used when the format specifier contains a
 * {@code '<'} (<tt>'&#92;u003c'</tt>) flag which causes the argument for
 * the previous format specifier to be re-used.  If there is no previous
 * argument, then a {@link MissingFormatArgumentException} is thrown.
 *
 * <blockquote><pre>
 *    formatter.format("%s %s %&lt;s %&lt;s", "a", "b", "c", "d")
 *    // -&gt; "a b b b"
 *    // "c" and "d" are ignored because they are not referenced
 * </pre></blockquote>
 *
 * <li> <i>Ordinary indexing</i> is used when the format specifier contains
 * neither an argument index nor a {@code '<'} flag.  Each format specifier
 * which uses ordinary indexing is assigned a sequential implicit index into
 * argument list which is independent of the indices used by explicit or
 * relative indexing.
 *
 * <blockquote><pre>
 *   formatter.format("%s %s %s %s", "a", "b", "c", "d")
 *   // -&gt; "a b c d"
 * </pre></blockquote>
 *
 * </ul>
 *
 * <p> It is possible to have a format string which uses all forms of indexing,
 * for example:
 *
 * <blockquote><pre>
 *   formatter.format("%2$s %s %&lt;s %s", "a", "b", "c", "d")
 *   // -&gt; "b a a b"
 *   // "c" and "d" are ignored because they are not referenced
 * </pre></blockquote>
 *
 * <p> The maximum number of arguments is limited by the maximum dimension of a
 * Java array as defined by
 * <cite>The Java&trade; Virtual Machine Specification</cite>.
 * If the argument index is does not correspond to an
 * available argument, then a {@link MissingFormatArgumentException} is thrown.
 *
 * <p> If there are more arguments than format specifiers, the extra arguments
 * are ignored.
 *
 * <p> Unless otherwise specified, passing a {@code null} argument to any
 * method or constructor in this class will cause a {@link
 * NullPointerException} to be thrown.
 *
 * @author Iris Clark
 * @since 1.5
 */
public final class Formatter implements Closeable, Flushable {

  private Appendable a;
  private final Locale l;

  private IOException lastException;

  private final char zero;
  private static double scaleUp;

  // 1 (sign) + 19 (max # sig digits) + 1 ('.') + 1 ('e') + 1 (sign)
  // + 3 (max # exp digits) + 4 (error) = 30
  private static final int MAX_FD_CHARS = 30;

  /**
   * Returns a charset object for the given charset name.
   *
   * @throws NullPointerException is csn is null
   * @throws UnsupportedEncodingException if the charset is not supported
   */
  private static Charset toCharset(String csn)
      throws UnsupportedEncodingException {
    Objects.requireNonNull(csn, "charsetName");
    try {
      return Charset.forName(csn);
    } catch (IllegalCharsetNameException | UnsupportedCharsetException unused) {
      // UnsupportedEncodingException should be thrown
      throw new UnsupportedEncodingException(csn);
    }
  }

  private static final Appendable nonNullAppendable(Appendable a) {
    if (a == null) {
      return new StringBuilder();
    }

    return a;
  }

  /* Private constructors */
  private Formatter(Locale l, Appendable a) {
    this.a = a;
    this.l = l;
    this.zero = getZero(l);
  }

  private Formatter(Charset charset, Locale l, File file)
      throws FileNotFoundException {
    this(l,
        new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file), charset)));
  }

  /**
   * Constructs a new formatter.
   *
   * <p> The destination of the formatted output is a {@link StringBuilder}
   * which may be retrieved by invoking {@link #out out()} and whose
   * current content may be converted into a string by invoking {@link
   * #toString toString()}.  The locale used is the {@linkplain
   * Locale#getDefault(Locale.Category) default locale} for
   * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java
   * virtual machine.
   */
  public Formatter() {
    this(Locale.getDefault(Locale.Category.FORMAT), new StringBuilder());
  }

  /**
   * Constructs a new formatter with the specified destination.
   *
   * <p> The locale used is the {@linkplain
   * Locale#getDefault(Locale.Category) default locale} for
   * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java
   * virtual machine.
   *
   * @param a Destination for the formatted output.  If {@code a} is {@code null} then a {@link
   * StringBuilder} will be created.
   */
  public Formatter(Appendable a) {
    this(Locale.getDefault(Locale.Category.FORMAT), nonNullAppendable(a));
  }

  /**
   * Constructs a new formatter with the specified locale.
   *
   * <p> The destination of the formatted output is a {@link StringBuilder}
   * which may be retrieved by invoking {@link #out out()} and whose current
   * content may be converted into a string by invoking {@link #toString
   * toString()}.
   *
   * @param l The {@linkplain java.util.Locale locale} to apply during formatting.  If {@code l} is
   * {@code null} then no localization is applied.
   */
  public Formatter(Locale l) {
    this(l, new StringBuilder());
  }

  /**
   * Constructs a new formatter with the specified destination and locale.
   *
   * @param a Destination for the formatted output.  If {@code a} is {@code null} then a {@link
   * StringBuilder} will be created.
   * @param l The {@linkplain java.util.Locale locale} to apply during formatting.  If {@code l} is
   * {@code null} then no localization is applied.
   */
  public Formatter(Appendable a, Locale l) {
    this(l, nonNullAppendable(a));
  }

  /**
   * Constructs a new formatter with the specified file name.
   *
   * <p> The charset used is the {@linkplain
   * java.nio.charset.Charset#defaultCharset() default charset} for this
   * instance of the Java virtual machine.
   *
   * <p> The locale used is the {@linkplain
   * Locale#getDefault(Locale.Category) default locale} for
   * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java
   * virtual machine.
   *
   * @param fileName The name of the file to use as the destination of this formatter.  If the file
   * exists then it will be truncated to zero size; otherwise, a new file will be created.  The
   * output will be written to the file and is buffered.
   * @throws SecurityException If a security manager is present and {@link
   * SecurityManager#checkWrite checkWrite(fileName)} denies write access to the file
   * @throws FileNotFoundException If the given file name does not denote an existing, writable
   * regular file and a new regular file of that name cannot be created, or if some other error
   * occurs while opening or creating the file
   */
  public Formatter(String fileName) throws FileNotFoundException {
    this(Locale.getDefault(Locale.Category.FORMAT),
        new BufferedWriter(new OutputStreamWriter(new FileOutputStream(fileName))));
  }

  /**
   * Constructs a new formatter with the specified file name and charset.
   *
   * <p> The locale used is the {@linkplain
   * Locale#getDefault(Locale.Category) default locale} for
   * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java
   * virtual machine.
   *
   * @param fileName The name of the file to use as the destination of this formatter.  If the file
   * exists then it will be truncated to zero size; otherwise, a new file will be created.  The
   * output will be written to the file and is buffered.
   * @param csn The name of a supported {@linkplain java.nio.charset.Charset charset}
   * @throws FileNotFoundException If the given file name does not denote an existing, writable
   * regular file and a new regular file of that name cannot be created, or if some other error
   * occurs while opening or creating the file
   * @throws SecurityException If a security manager is present and {@link
   * SecurityManager#checkWrite checkWrite(fileName)} denies write access to the file
   * @throws UnsupportedEncodingException If the named charset is not supported
   */
  public Formatter(String fileName, String csn)
      throws FileNotFoundException, UnsupportedEncodingException {
    this(fileName, csn, Locale.getDefault(Locale.Category.FORMAT));
  }

  /**
   * Constructs a new formatter with the specified file name, charset, and
   * locale.
   *
   * @param fileName The name of the file to use as the destination of this formatter.  If the file
   * exists then it will be truncated to zero size; otherwise, a new file will be created.  The
   * output will be written to the file and is buffered.
   * @param csn The name of a supported {@linkplain java.nio.charset.Charset charset}
   * @param l The {@linkplain java.util.Locale locale} to apply during formatting.  If {@code l} is
   * {@code null} then no localization is applied.
   * @throws FileNotFoundException If the given file name does not denote an existing, writable
   * regular file and a new regular file of that name cannot be created, or if some other error
   * occurs while opening or creating the file
   * @throws SecurityException If a security manager is present and {@link
   * SecurityManager#checkWrite checkWrite(fileName)} denies write access to the file
   * @throws UnsupportedEncodingException If the named charset is not supported
   */
  public Formatter(String fileName, String csn, Locale l)
      throws FileNotFoundException, UnsupportedEncodingException {
    this(toCharset(csn), l, new File(fileName));
  }

  /**
   * Constructs a new formatter with the specified file.
   *
   * <p> The charset used is the {@linkplain
   * java.nio.charset.Charset#defaultCharset() default charset} for this
   * instance of the Java virtual machine.
   *
   * <p> The locale used is the {@linkplain
   * Locale#getDefault(Locale.Category) default locale} for
   * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java
   * virtual machine.
   *
   * @param file The file to use as the destination of this formatter.  If the file exists then it
   * will be truncated to zero size; otherwise, a new file will be created.  The output will be
   * written to the file and is buffered.
   * @throws SecurityException If a security manager is present and {@link
   * SecurityManager#checkWrite checkWrite(file.getPath())} denies write access to the file
   * @throws FileNotFoundException If the given file object does not denote an existing, writable
   * regular file and a new regular file of that name cannot be created, or if some other error
   * occurs while opening or creating the file
   */
  public Formatter(File file) throws FileNotFoundException {
    this(Locale.getDefault(Locale.Category.FORMAT),
        new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file))));
  }

  /**
   * Constructs a new formatter with the specified file and charset.
   *
   * <p> The locale used is the {@linkplain
   * Locale#getDefault(Locale.Category) default locale} for
   * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java
   * virtual machine.
   *
   * @param file The file to use as the destination of this formatter.  If the file exists then it
   * will be truncated to zero size; otherwise, a new file will be created.  The output will be
   * written to the file and is buffered.
   * @param csn The name of a supported {@linkplain java.nio.charset.Charset charset}
   * @throws FileNotFoundException If the given file object does not denote an existing, writable
   * regular file and a new regular file of that name cannot be created, or if some other error
   * occurs while opening or creating the file
   * @throws SecurityException If a security manager is present and {@link
   * SecurityManager#checkWrite checkWrite(file.getPath())} denies write access to the file
   * @throws UnsupportedEncodingException If the named charset is not supported
   */
  public Formatter(File file, String csn)
      throws FileNotFoundException, UnsupportedEncodingException {
    this(file, csn, Locale.getDefault(Locale.Category.FORMAT));
  }

  /**
   * Constructs a new formatter with the specified file, charset, and
   * locale.
   *
   * @param file The file to use as the destination of this formatter.  If the file exists then it
   * will be truncated to zero size; otherwise, a new file will be created.  The output will be
   * written to the file and is buffered.
   * @param csn The name of a supported {@linkplain java.nio.charset.Charset charset}
   * @param l The {@linkplain java.util.Locale locale} to apply during formatting.  If {@code l} is
   * {@code null} then no localization is applied.
   * @throws FileNotFoundException If the given file object does not denote an existing, writable
   * regular file and a new regular file of that name cannot be created, or if some other error
   * occurs while opening or creating the file
   * @throws SecurityException If a security manager is present and {@link
   * SecurityManager#checkWrite checkWrite(file.getPath())} denies write access to the file
   * @throws UnsupportedEncodingException If the named charset is not supported
   */
  public Formatter(File file, String csn, Locale l)
      throws FileNotFoundException, UnsupportedEncodingException {
    this(toCharset(csn), l, file);
  }

  /**
   * Constructs a new formatter with the specified print stream.
   *
   * <p> The locale used is the {@linkplain
   * Locale#getDefault(Locale.Category) default locale} for
   * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java
   * virtual machine.
   *
   * <p> Characters are written to the given {@link java.io.PrintStream
   * PrintStream} object and are therefore encoded using that object's
   * charset.
   *
   * @param ps The stream to use as the destination of this formatter.
   */
  public Formatter(PrintStream ps) {
    this(Locale.getDefault(Locale.Category.FORMAT),
        (Appendable) Objects.requireNonNull(ps));
  }

  /**
   * Constructs a new formatter with the specified output stream.
   *
   * <p> The charset used is the {@linkplain
   * java.nio.charset.Charset#defaultCharset() default charset} for this
   * instance of the Java virtual machine.
   *
   * <p> The locale used is the {@linkplain
   * Locale#getDefault(Locale.Category) default locale} for
   * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java
   * virtual machine.
   *
   * @param os The output stream to use as the destination of this formatter. The output will be
   * buffered.
   */
  public Formatter(OutputStream os) {
    this(Locale.getDefault(Locale.Category.FORMAT),
        new BufferedWriter(new OutputStreamWriter(os)));
  }

  /**
   * Constructs a new formatter with the specified output stream and
   * charset.
   *
   * <p> The locale used is the {@linkplain
   * Locale#getDefault(Locale.Category) default locale} for
   * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java
   * virtual machine.
   *
   * @param os The output stream to use as the destination of this formatter. The output will be
   * buffered.
   * @param csn The name of a supported {@linkplain java.nio.charset.Charset charset}
   * @throws UnsupportedEncodingException If the named charset is not supported
   */
  public Formatter(OutputStream os, String csn)
      throws UnsupportedEncodingException {
    this(os, csn, Locale.getDefault(Locale.Category.FORMAT));
  }

  /**
   * Constructs a new formatter with the specified output stream, charset,
   * and locale.
   *
   * @param os The output stream to use as the destination of this formatter. The output will be
   * buffered.
   * @param csn The name of a supported {@linkplain java.nio.charset.Charset charset}
   * @param l The {@linkplain java.util.Locale locale} to apply during formatting.  If {@code l} is
   * {@code null} then no localization is applied.
   * @throws UnsupportedEncodingException If the named charset is not supported
   */
  public Formatter(OutputStream os, String csn, Locale l)
      throws UnsupportedEncodingException {
    this(l, new BufferedWriter(new OutputStreamWriter(os, csn)));
  }

  private static char getZero(Locale l) {
    if ((l != null) && !l.equals(Locale.US)) {
      DecimalFormatSymbols dfs = DecimalFormatSymbols.getInstance(l);
      return dfs.getZeroDigit();
    } else {
      return '0';
    }
  }

  /**
   * Returns the locale set by the construction of this formatter.
   *
   * <p> The {@link #format(java.util.Locale, String, Object...) format} method
   * for this object which has a locale argument does not change this value.
   *
   * @return {@code null} if no localization is applied, otherwise a locale
   * @throws FormatterClosedException If this formatter has been closed by invoking its {@link
   * #close()} method
   */
  public Locale locale() {
    ensureOpen();
    return l;
  }

  /**
   * Returns the destination for the output.
   *
   * @return The destination for the output
   * @throws FormatterClosedException If this formatter has been closed by invoking its {@link
   * #close()} method
   */
  public Appendable out() {
    ensureOpen();
    return a;
  }

  /**
   * Returns the result of invoking {@code toString()} on the destination
   * for the output.  For example, the following code formats text into a
   * {@link StringBuilder} then retrieves the resultant string:
   *
   * <blockquote><pre>
   *   Formatter f = new Formatter();
   *   f.format("Last reboot at %tc", lastRebootDate);
   *   String s = f.toString();
   *   // -&gt; s == "Last reboot at Sat Jan 01 00:00:00 PST 2000"
   * </pre></blockquote>
   *
   * <p> An invocation of this method behaves in exactly the same way as the
   * invocation
   *
   * <pre>
   *     out().toString() </pre>
   *
   * <p> Depending on the specification of {@code toString} for the {@link
   * Appendable}, the returned string may or may not contain the characters
   * written to the destination.  For instance, buffers typically return
   * their contents in {@code toString()}, but streams cannot since the
   * data is discarded.
   *
   * @return The result of invoking {@code toString()} on the destination for the output
   * @throws FormatterClosedException If this formatter has been closed by invoking its {@link
   * #close()} method
   */
  public String toString() {
    ensureOpen();
    return a.toString();
  }

  /**
   * Flushes this formatter.  If the destination implements the {@link
   * java.io.Flushable} interface, its {@code flush} method will be invoked.
   *
   * <p> Flushing a formatter writes any buffered output in the destination
   * to the underlying stream.
   *
   * @throws FormatterClosedException If this formatter has been closed by invoking its {@link
   * #close()} method
   */
  public void flush() {
    ensureOpen();
    if (a instanceof Flushable) {
      try {
        ((Flushable) a).flush();
      } catch (IOException ioe) {
        lastException = ioe;
      }
    }
  }

  /**
   * Closes this formatter.  If the destination implements the {@link
   * java.io.Closeable} interface, its {@code close} method will be invoked.
   *
   * <p> Closing a formatter allows it to release resources it may be holding
   * (such as open files).  If the formatter is already closed, then invoking
   * this method has no effect.
   *
   * <p> Attempting to invoke any methods except {@link #ioException()} in
   * this formatter after it has been closed will result in a {@link
   * FormatterClosedException}.
   */
  public void close() {
    if (a == null) {
      return;
    }
    try {
      if (a instanceof Closeable) {
        ((Closeable) a).close();
      }
    } catch (IOException ioe) {
      lastException = ioe;
    } finally {
      a = null;
    }
  }

  private void ensureOpen() {
    if (a == null) {
      throw new FormatterClosedException();
    }
  }

  /**
   * Returns the {@code IOException} last thrown by this formatter's {@link
   * Appendable}.
   *
   * <p> If the destination's {@code append()} method never throws
   * {@code IOException}, then this method will always return {@code null}.
   *
   * @return The last exception thrown by the Appendable or {@code null} if no such exception
   * exists.
   */
  public IOException ioException() {
    return lastException;
  }

  /**
   * Writes a formatted string to this object's destination using the
   * specified format string and arguments.  The locale used is the one
   * defined during the construction of this formatter.
   *
   * @param format A format string as described in <a href="#syntax">Format string syntax</a>.
   * @param args Arguments referenced by the format specifiers in the format string.  If there are
   * more arguments than format specifiers, the extra arguments are ignored.  The maximum number of
   * arguments is limited by the maximum dimension of a Java array as defined by <cite>The
   * Java&trade; Virtual Machine Specification</cite>.
   * @return This formatter
   * @throws IllegalFormatException If a format string contains an illegal syntax, a format
   * specifier that is incompatible with the given arguments, insufficient arguments given the
   * format string, or other illegal conditions.  For specification of all possible formatting
   * errors, see the <a href="#detail">Details</a> section of the formatter class specification.
   * @throws FormatterClosedException If this formatter has been closed by invoking its {@link
   * #close()} method
   */
  public Formatter format(String format, Object... args) {
    return format(l, format, args);
  }

  /**
   * Writes a formatted string to this object's destination using the
   * specified locale, format string, and arguments.
   *
   * @param l The {@linkplain java.util.Locale locale} to apply during formatting.  If {@code l} is
   * {@code null} then no localization is applied.  This does not change this object's locale that
   * was set during construction.
   * @param format A format string as described in <a href="#syntax">Format string syntax</a>
   * @param args Arguments referenced by the format specifiers in the format string.  If there are
   * more arguments than format specifiers, the extra arguments are ignored.  The maximum number of
   * arguments is limited by the maximum dimension of a Java array as defined by <cite>The
   * Java&trade; Virtual Machine Specification</cite>.
   * @return This formatter
   * @throws IllegalFormatException If a format string contains an illegal syntax, a format
   * specifier that is incompatible with the given arguments, insufficient arguments given the
   * format string, or other illegal conditions.  For specification of all possible formatting
   * errors, see the <a href="#detail">Details</a> section of the formatter class specification.
   * @throws FormatterClosedException If this formatter has been closed by invoking its {@link
   * #close()} method
   */
  public Formatter format(Locale l, String format, Object... args) {
    ensureOpen();

    // index of last argument referenced
    int last = -1;
    // last ordinary index
    int lasto = -1;

    FormatString[] fsa = parse(format);
    for (int i = 0; i < fsa.length; i++) {
      FormatString fs = fsa[i];
      int index = fs.index();
      try {
        switch (index) {
          case -2:  // fixed string, "%n", or "%%"
            fs.print(null, l);
            break;
          case -1:  // relative index
            if (last < 0 || (args != null && last > args.length - 1)) {
              throw new MissingFormatArgumentException(fs.toString());
            }
            fs.print((args == null ? null : args[last]), l);
            break;
          case 0:  // ordinary index
            lasto++;
            last = lasto;
            if (args != null && lasto > args.length - 1) {
              throw new MissingFormatArgumentException(fs.toString());
            }
            fs.print((args == null ? null : args[lasto]), l);
            break;
          default:  // explicit index
            last = index - 1;
            if (args != null && last > args.length - 1) {
              throw new MissingFormatArgumentException(fs.toString());
            }
            fs.print((args == null ? null : args[last]), l);
            break;
        }
      } catch (IOException x) {
        lastException = x;
      }
    }
    return this;
  }

  // %[argument_index$][flags][width][.precision][t]conversion
  private static final String formatSpecifier
      = "%(\\d+\\$)?([-#+ 0,(\\<]*)?(\\d+)?(\\.\\d+)?([tT])?([a-zA-Z%])";

  private static Pattern fsPattern = Pattern.compile(formatSpecifier);

  /**
   * Finds format specifiers in the format string.
   */
  private FormatString[] parse(String s) {
    ArrayList<FormatString> al = new ArrayList<>();
    Matcher m = fsPattern.matcher(s);
    for (int i = 0, len = s.length(); i < len; ) {
      if (m.find(i)) {
        // Anything between the start of the string and the beginning
        // of the format specifier is either fixed text or contains
        // an invalid format string.
        if (m.start() != i) {
          // Make sure we didn't miss any invalid format specifiers
          checkText(s, i, m.start());
          // Assume previous characters were fixed text
          al.add(new FixedString(s.substring(i, m.start())));
        }

        al.add(new FormatSpecifier(m));
        i = m.end();
      } else {
        // No more valid format specifiers.  Check for possible invalid
        // format specifiers.
        checkText(s, i, len);
        // The rest of the string is fixed text
        al.add(new FixedString(s.substring(i)));
        break;
      }
    }
    return al.toArray(new FormatString[al.size()]);
  }

  private static void checkText(String s, int start, int end) {
    for (int i = start; i < end; i++) {
      // Any '%' found in the region starts an invalid format specifier.
      if (s.charAt(i) == '%') {
        char c = (i == end - 1) ? '%' : s.charAt(i + 1);
        throw new UnknownFormatConversionException(String.valueOf(c));
      }
    }
  }

  private interface FormatString {

    int index();

    void print(Object arg, Locale l) throws IOException;

    String toString();
  }

  private class FixedString implements FormatString {

    private String s;

    FixedString(String s) {
      this.s = s;
    }

    public int index() {
      return -2;
    }

    public void print(Object arg, Locale l)
        throws IOException {
      a.append(s);
    }

    public String toString() {
      return s;
    }
  }

  /**
   * Enum for {@code BigDecimal} formatting.
   */
  public enum BigDecimalLayoutForm {
    /**
     * Format the {@code BigDecimal} in computerized scientific notation.
     */
    SCIENTIFIC,

    /**
     * Format the {@code BigDecimal} as a decimal number.
     */
    DECIMAL_FLOAT
  }

  ;

  private class FormatSpecifier implements FormatString {

    private int index = -1;
    private Flags f = Flags.NONE;
    private int width;
    private int precision;
    private boolean dt = false;
    private char c;

    private int index(String s) {
      if (s != null) {
        try {
          index = Integer.parseInt(s.substring(0, s.length() - 1));
        } catch (NumberFormatException x) {
          assert (false);
        }
      } else {
        index = 0;
      }
      return index;
    }

    public int index() {
      return index;
    }

    private Flags flags(String s) {
      f = Flags.parse(s);
      if (f.contains(Flags.PREVIOUS)) {
        index = -1;
      }
      return f;
    }

    Flags flags() {
      return f;
    }

    private int width(String s) {
      width = -1;
      if (s != null) {
        try {
          width = Integer.parseInt(s);
          if (width < 0) {
            throw new IllegalFormatWidthException(width);
          }
        } catch (NumberFormatException x) {
          assert (false);
        }
      }
      return width;
    }

    int width() {
      return width;
    }

    private int precision(String s) {
      precision = -1;
      if (s != null) {
        try {
          // remove the '.'
          precision = Integer.parseInt(s.substring(1));
          if (precision < 0) {
            throw new IllegalFormatPrecisionException(precision);
          }
        } catch (NumberFormatException x) {
          assert (false);
        }
      }
      return precision;
    }

    int precision() {
      return precision;
    }

    private char conversion(String s) {
      c = s.charAt(0);
      if (!dt) {
        if (!Conversion.isValid(c)) {
          throw new UnknownFormatConversionException(String.valueOf(c));
        }
        if (Character.isUpperCase(c)) {
          f.add(Flags.UPPERCASE);
        }
        c = Character.toLowerCase(c);
        if (Conversion.isText(c)) {
          index = -2;
        }
      }
      return c;
    }

    private char conversion() {
      return c;
    }

    FormatSpecifier(Matcher m) {
      int idx = 1;

      index(m.group(idx++));
      flags(m.group(idx++));
      width(m.group(idx++));
      precision(m.group(idx++));

      String tT = m.group(idx++);
      if (tT != null) {
        dt = true;
        if (tT.equals("T")) {
          f.add(Flags.UPPERCASE);
        }
      }

      conversion(m.group(idx));

      if (dt) {
        checkDateTime();
      } else if (Conversion.isGeneral(c)) {
        checkGeneral();
      } else if (Conversion.isCharacter(c)) {
        checkCharacter();
      } else if (Conversion.isInteger(c)) {
        checkInteger();
      } else if (Conversion.isFloat(c)) {
        checkFloat();
      } else if (Conversion.isText(c)) {
        checkText();
      } else {
        throw new UnknownFormatConversionException(String.valueOf(c));
      }
    }

    public void print(Object arg, Locale l) throws IOException {
      if (dt) {
        printDateTime(arg, l);
        return;
      }
      switch (c) {
        case Conversion.DECIMAL_INTEGER:
        case Conversion.OCTAL_INTEGER:
        case Conversion.HEXADECIMAL_INTEGER:
          printInteger(arg, l);
          break;
        case Conversion.SCIENTIFIC:
        case Conversion.GENERAL:
        case Conversion.DECIMAL_FLOAT:
        case Conversion.HEXADECIMAL_FLOAT:
          printFloat(arg, l);
          break;
        case Conversion.CHARACTER:
        case Conversion.CHARACTER_UPPER:
          printCharacter(arg);
          break;
        case Conversion.BOOLEAN:
          printBoolean(arg);
          break;
        case Conversion.STRING:
          printString(arg, l);
          break;
        case Conversion.HASHCODE:
          printHashCode(arg);
          break;
        case Conversion.LINE_SEPARATOR:
          a.append(System.lineSeparator());
          break;
        case Conversion.PERCENT_SIGN:
          a.append('%');
          break;
        default:
          assert false;
      }
    }

    private void printInteger(Object arg, Locale l) throws IOException {
      if (arg == null) {
        print("null");
      } else if (arg instanceof Byte) {
        print(((Byte) arg).byteValue(), l);
      } else if (arg instanceof Short) {
        print(((Short) arg).shortValue(), l);
      } else if (arg instanceof Integer) {
        print(((Integer) arg).intValue(), l);
      } else if (arg instanceof Long) {
        print(((Long) arg).longValue(), l);
      } else if (arg instanceof BigInteger) {
        print(((BigInteger) arg), l);
      } else {
        failConversion(c, arg);
      }
    }

    private void printFloat(Object arg, Locale l) throws IOException {
      if (arg == null) {
        print("null");
      } else if (arg instanceof Float) {
        print(((Float) arg).floatValue(), l);
      } else if (arg instanceof Double) {
        print(((Double) arg).doubleValue(), l);
      } else if (arg instanceof BigDecimal) {
        print(((BigDecimal) arg), l);
      } else {
        failConversion(c, arg);
      }
    }

    private void printDateTime(Object arg, Locale l) throws IOException {
      if (arg == null) {
        print("null");
        return;
      }
      Calendar cal = null;

      // Instead of Calendar.setLenient(true), perhaps we should
      // wrap the IllegalArgumentException that might be thrown?
      if (arg instanceof Long) {
        // Note that the following method uses an instance of the
        // default time zone (TimeZone.getDefaultRef().
        cal = Calendar.getInstance(l == null ? Locale.US : l);
        cal.setTimeInMillis((Long) arg);
      } else if (arg instanceof Date) {
        // Note that the following method uses an instance of the
        // default time zone (TimeZone.getDefaultRef().
        cal = Calendar.getInstance(l == null ? Locale.US : l);
        cal.setTime((Date) arg);
      } else if (arg instanceof Calendar) {
        cal = (Calendar) ((Calendar) arg).clone();
        cal.setLenient(true);
      } else if (arg instanceof TemporalAccessor) {
        print((TemporalAccessor) arg, c, l);
        return;
      } else {
        failConversion(c, arg);
      }
      // Use the provided locale so that invocations of
      // localizedMagnitude() use optimizations for null.
      print(cal, c, l);
    }

    private void printCharacter(Object arg) throws IOException {
      if (arg == null) {
        print("null");
        return;
      }
      String s = null;
      if (arg instanceof Character) {
        s = ((Character) arg).toString();
      } else if (arg instanceof Byte) {
        byte i = ((Byte) arg).byteValue();
        if (Character.isValidCodePoint(i)) {
          s = new String(Character.toChars(i));
        } else {
          throw new IllegalFormatCodePointException(i);
        }
      } else if (arg instanceof Short) {
        short i = ((Short) arg).shortValue();
        if (Character.isValidCodePoint(i)) {
          s = new String(Character.toChars(i));
        } else {
          throw new IllegalFormatCodePointException(i);
        }
      } else if (arg instanceof Integer) {
        int i = ((Integer) arg).intValue();
        if (Character.isValidCodePoint(i)) {
          s = new String(Character.toChars(i));
        } else {
          throw new IllegalFormatCodePointException(i);
        }
      } else {
        failConversion(c, arg);
      }
      print(s);
    }

    private void printString(Object arg, Locale l) throws IOException {
      if (arg instanceof Formattable) {
        Formatter fmt = Formatter.this;
        if (fmt.locale() != l) {
          fmt = new Formatter(fmt.out(), l);
        }
        ((Formattable) arg).formatTo(fmt, f.valueOf(), width, precision);
      } else {
        if (f.contains(Flags.ALTERNATE)) {
          failMismatch(Flags.ALTERNATE, 's');
        }
        if (arg == null) {
          print("null");
        } else {
          print(arg.toString());
        }
      }
    }

    private void printBoolean(Object arg) throws IOException {
      String s;
      if (arg != null) {
        s = ((arg instanceof Boolean)
            ? ((Boolean) arg).toString()
            : Boolean.toString(true));
      } else {
        s = Boolean.toString(false);
      }
      print(s);
    }

    private void printHashCode(Object arg) throws IOException {
      String s = (arg == null
          ? "null"
          : Integer.toHexString(arg.hashCode()));
      print(s);
    }

    private void print(String s) throws IOException {
      if (precision != -1 && precision < s.length()) {
        s = s.substring(0, precision);
      }
      if (f.contains(Flags.UPPERCASE)) {
        s = s.toUpperCase();
      }
      a.append(justify(s));
    }

    private String justify(String s) {
      if (width == -1) {
        return s;
      }
      StringBuilder sb = new StringBuilder();
      boolean pad = f.contains(Flags.LEFT_JUSTIFY);
      int sp = width - s.length();
      if (!pad) {
        for (int i = 0; i < sp; i++) {
          sb.append(' ');
        }
      }
      sb.append(s);
      if (pad) {
        for (int i = 0; i < sp; i++) {
          sb.append(' ');
        }
      }
      return sb.toString();
    }

    public String toString() {
      StringBuilder sb = new StringBuilder("%");
      // Flags.UPPERCASE is set internally for legal conversions.
      Flags dupf = f.dup().remove(Flags.UPPERCASE);
      sb.append(dupf.toString());
      if (index > 0) {
        sb.append(index).append('$');
      }
      if (width != -1) {
        sb.append(width);
      }
      if (precision != -1) {
        sb.append('.').append(precision);
      }
      if (dt) {
        sb.append(f.contains(Flags.UPPERCASE) ? 'T' : 't');
      }
      sb.append(f.contains(Flags.UPPERCASE)
          ? Character.toUpperCase(c) : c);
      return sb.toString();
    }

    private void checkGeneral() {
      if ((c == Conversion.BOOLEAN || c == Conversion.HASHCODE)
          && f.contains(Flags.ALTERNATE)) {
        failMismatch(Flags.ALTERNATE, c);
      }
      // '-' requires a width
      if (width == -1 && f.contains(Flags.LEFT_JUSTIFY)) {
        throw new MissingFormatWidthException(toString());
      }
      checkBadFlags(Flags.PLUS, Flags.LEADING_SPACE, Flags.ZERO_PAD,
          Flags.GROUP, Flags.PARENTHESES);
    }

    private void checkDateTime() {
      if (precision != -1) {
        throw new IllegalFormatPrecisionException(precision);
      }
      if (!DateTime.isValid(c)) {
        throw new UnknownFormatConversionException("t" + c);
      }
      checkBadFlags(Flags.ALTERNATE, Flags.PLUS, Flags.LEADING_SPACE,
          Flags.ZERO_PAD, Flags.GROUP, Flags.PARENTHESES);
      // '-' requires a width
      if (width == -1 && f.contains(Flags.LEFT_JUSTIFY)) {
        throw new MissingFormatWidthException(toString());
      }
    }

    private void checkCharacter() {
      if (precision != -1) {
        throw new IllegalFormatPrecisionException(precision);
      }
      checkBadFlags(Flags.ALTERNATE, Flags.PLUS, Flags.LEADING_SPACE,
          Flags.ZERO_PAD, Flags.GROUP, Flags.PARENTHESES);
      // '-' requires a width
      if (width == -1 && f.contains(Flags.LEFT_JUSTIFY)) {
        throw new MissingFormatWidthException(toString());
      }
    }

    private void checkInteger() {
      checkNumeric();
      if (precision != -1) {
        throw new IllegalFormatPrecisionException(precision);
      }

      if (c == Conversion.DECIMAL_INTEGER) {
        checkBadFlags(Flags.ALTERNATE);
      } else if (c == Conversion.OCTAL_INTEGER) {
        checkBadFlags(Flags.GROUP);
      } else {
        checkBadFlags(Flags.GROUP);
      }
    }

    private void checkBadFlags(Flags... badFlags) {
      for (int i = 0; i < badFlags.length; i++) {
        if (f.contains(badFlags[i])) {
          failMismatch(badFlags[i], c);
        }
      }
    }

    private void checkFloat() {
      checkNumeric();
      if (c == Conversion.DECIMAL_FLOAT) {
      } else if (c == Conversion.HEXADECIMAL_FLOAT) {
        checkBadFlags(Flags.PARENTHESES, Flags.GROUP);
      } else if (c == Conversion.SCIENTIFIC) {
        checkBadFlags(Flags.GROUP);
      } else if (c == Conversion.GENERAL) {
        checkBadFlags(Flags.ALTERNATE);
      }
    }

    private void checkNumeric() {
      if (width != -1 && width < 0) {
        throw new IllegalFormatWidthException(width);
      }

      if (precision != -1 && precision < 0) {
        throw new IllegalFormatPrecisionException(precision);
      }

      // '-' and '0' require a width
      if (width == -1
          && (f.contains(Flags.LEFT_JUSTIFY) || f.contains(Flags.ZERO_PAD))) {
        throw new MissingFormatWidthException(toString());
      }

      // bad combination
      if ((f.contains(Flags.PLUS) && f.contains(Flags.LEADING_SPACE))
          || (f.contains(Flags.LEFT_JUSTIFY) && f.contains(Flags.ZERO_PAD))) {
        throw new IllegalFormatFlagsException(f.toString());
      }
    }

    private void checkText() {
      if (precision != -1) {
        throw new IllegalFormatPrecisionException(precision);
      }
      switch (c) {
        case Conversion.PERCENT_SIGN:
          if (f.valueOf() != Flags.LEFT_JUSTIFY.valueOf()
              && f.valueOf() != Flags.NONE.valueOf()) {
            throw new IllegalFormatFlagsException(f.toString());
          }
          // '-' requires a width
          if (width == -1 && f.contains(Flags.LEFT_JUSTIFY)) {
            throw new MissingFormatWidthException(toString());
          }
          break;
        case Conversion.LINE_SEPARATOR:
          if (width != -1) {
            throw new IllegalFormatWidthException(width);
          }
          if (f.valueOf() != Flags.NONE.valueOf()) {
            throw new IllegalFormatFlagsException(f.toString());
          }
          break;
        default:
          assert false;
      }
    }

    private void print(byte value, Locale l) throws IOException {
      long v = value;
      if (value < 0
          && (c == Conversion.OCTAL_INTEGER
          || c == Conversion.HEXADECIMAL_INTEGER)) {
        v += (1L << 8);
        assert v >= 0 : v;
      }
      print(v, l);
    }

    private void print(short value, Locale l) throws IOException {
      long v = value;
      if (value < 0
          && (c == Conversion.OCTAL_INTEGER
          || c == Conversion.HEXADECIMAL_INTEGER)) {
        v += (1L << 16);
        assert v >= 0 : v;
      }
      print(v, l);
    }

    private void print(int value, Locale l) throws IOException {
      long v = value;
      if (value < 0
          && (c == Conversion.OCTAL_INTEGER
          || c == Conversion.HEXADECIMAL_INTEGER)) {
        v += (1L << 32);
        assert v >= 0 : v;
      }
      print(v, l);
    }

    private void print(long value, Locale l) throws IOException {

      StringBuilder sb = new StringBuilder();

      if (c == Conversion.DECIMAL_INTEGER) {
        boolean neg = value < 0;
        char[] va;
        if (value < 0) {
          va = Long.toString(value, 10).substring(1).toCharArray();
        } else {
          va = Long.toString(value, 10).toCharArray();
        }

        // leading sign indicator
        leadingSign(sb, neg);

        // the value
        localizedMagnitude(sb, va, f, adjustWidth(width, f, neg), l);

        // trailing sign indicator
        trailingSign(sb, neg);
      } else if (c == Conversion.OCTAL_INTEGER) {
        checkBadFlags(Flags.PARENTHESES, Flags.LEADING_SPACE,
            Flags.PLUS);
        String s = Long.toOctalString(value);
        int len = (f.contains(Flags.ALTERNATE)
            ? s.length() + 1
            : s.length());

        // apply ALTERNATE (radix indicator for octal) before ZERO_PAD
        if (f.contains(Flags.ALTERNATE)) {
          sb.append('0');
        }
        if (f.contains(Flags.ZERO_PAD)) {
          for (int i = 0; i < width - len; i++) {
            sb.append('0');
          }
        }
        sb.append(s);
      } else if (c == Conversion.HEXADECIMAL_INTEGER) {
        checkBadFlags(Flags.PARENTHESES, Flags.LEADING_SPACE,
            Flags.PLUS);
        String s = Long.toHexString(value);
        int len = (f.contains(Flags.ALTERNATE)
            ? s.length() + 2
            : s.length());

        // apply ALTERNATE (radix indicator for hex) before ZERO_PAD
        if (f.contains(Flags.ALTERNATE)) {
          sb.append(f.contains(Flags.UPPERCASE) ? "0X" : "0x");
        }
        if (f.contains(Flags.ZERO_PAD)) {
          for (int i = 0; i < width - len; i++) {
            sb.append('0');
          }
        }
        if (f.contains(Flags.UPPERCASE)) {
          s = s.toUpperCase();
        }
        sb.append(s);
      }

      // justify based on width
      a.append(justify(sb.toString()));
    }

    // neg := val < 0
    private StringBuilder leadingSign(StringBuilder sb, boolean neg) {
      if (!neg) {
        if (f.contains(Flags.PLUS)) {
          sb.append('+');
        } else if (f.contains(Flags.LEADING_SPACE)) {
          sb.append(' ');
        }
      } else {
        if (f.contains(Flags.PARENTHESES)) {
          sb.append('(');
        } else {
          sb.append('-');
        }
      }
      return sb;
    }

    // neg := val < 0
    private StringBuilder trailingSign(StringBuilder sb, boolean neg) {
      if (neg && f.contains(Flags.PARENTHESES)) {
        sb.append(')');
      }
      return sb;
    }

    private void print(BigInteger value, Locale l) throws IOException {
      StringBuilder sb = new StringBuilder();
      boolean neg = value.signum() == -1;
      BigInteger v = value.abs();

      // leading sign indicator
      leadingSign(sb, neg);

      // the value
      if (c == Conversion.DECIMAL_INTEGER) {
        char[] va = v.toString().toCharArray();
        localizedMagnitude(sb, va, f, adjustWidth(width, f, neg), l);
      } else if (c == Conversion.OCTAL_INTEGER) {
        String s = v.toString(8);

        int len = s.length() + sb.length();
        if (neg && f.contains(Flags.PARENTHESES)) {
          len++;
        }

        // apply ALTERNATE (radix indicator for octal) before ZERO_PAD
        if (f.contains(Flags.ALTERNATE)) {
          len++;
          sb.append('0');
        }
        if (f.contains(Flags.ZERO_PAD)) {
          for (int i = 0; i < width - len; i++) {
            sb.append('0');
          }
        }
        sb.append(s);
      } else if (c == Conversion.HEXADECIMAL_INTEGER) {
        String s = v.toString(16);

        int len = s.length() + sb.length();
        if (neg && f.contains(Flags.PARENTHESES)) {
          len++;
        }

        // apply ALTERNATE (radix indicator for hex) before ZERO_PAD
        if (f.contains(Flags.ALTERNATE)) {
          len += 2;
          sb.append(f.contains(Flags.UPPERCASE) ? "0X" : "0x");
        }
        if (f.contains(Flags.ZERO_PAD)) {
          for (int i = 0; i < width - len; i++) {
            sb.append('0');
          }
        }
        if (f.contains(Flags.UPPERCASE)) {
          s = s.toUpperCase();
        }
        sb.append(s);
      }

      // trailing sign indicator
      trailingSign(sb, (value.signum() == -1));

      // justify based on width
      a.append(justify(sb.toString()));
    }

    private void print(float value, Locale l) throws IOException {
      print((double) value, l);
    }

    private void print(double value, Locale l) throws IOException {
      StringBuilder sb = new StringBuilder();
      boolean neg = Double.compare(value, 0.0) == -1;

      if (!Double.isNaN(value)) {
        double v = Math.abs(value);

        // leading sign indicator
        leadingSign(sb, neg);

        // the value
        if (!Double.isInfinite(v)) {
          print(sb, v, l, f, c, precision, neg);
        } else {
          sb.append(f.contains(Flags.UPPERCASE)
              ? "INFINITY" : "Infinity");
        }

        // trailing sign indicator
        trailingSign(sb, neg);
      } else {
        sb.append(f.contains(Flags.UPPERCASE) ? "NAN" : "NaN");
      }

      // justify based on width
      a.append(justify(sb.toString()));
    }

    // !Double.isInfinite(value) && !Double.isNaN(value)
    private void print(StringBuilder sb, double value, Locale l,
        Flags f, char c, int precision, boolean neg)
        throws IOException {
      if (c == Conversion.SCIENTIFIC) {
        // Create a new FormattedFloatingDecimal with the desired
        // precision.
        int prec = (precision == -1 ? 6 : precision);

        FormattedFloatingDecimal fd
            = FormattedFloatingDecimal.valueOf(value, prec,
            FormattedFloatingDecimal.Form.SCIENTIFIC);

        char[] mant = addZeros(fd.getMantissa(), prec);

        // If the precision is zero and the '#' flag is set, add the
        // requested decimal point.
        if (f.contains(Flags.ALTERNATE) && (prec == 0)) {
          mant = addDot(mant);
        }

        char[] exp = (value == 0.0)
            ? new char[]{'+', '0', '0'} : fd.getExponent();

        int newW = width;
        if (width != -1) {
          newW = adjustWidth(width - exp.length - 1, f, neg);
        }
        localizedMagnitude(sb, mant, f, newW, l);

        sb.append(f.contains(Flags.UPPERCASE) ? 'E' : 'e');

        Flags flags = f.dup().remove(Flags.GROUP);
        char sign = exp[0];
        assert (sign == '+' || sign == '-');
        sb.append(sign);

        char[] tmp = new char[exp.length - 1];
        System.arraycopy(exp, 1, tmp, 0, exp.length - 1);
        sb.append(localizedMagnitude(null, tmp, flags, -1, l));
      } else if (c == Conversion.DECIMAL_FLOAT) {
        // Create a new FormattedFloatingDecimal with the desired
        // precision.
        int prec = (precision == -1 ? 6 : precision);

        FormattedFloatingDecimal fd
            = FormattedFloatingDecimal.valueOf(value, prec,
            FormattedFloatingDecimal.Form.DECIMAL_FLOAT);

        char[] mant = addZeros(fd.getMantissa(), prec);

        // If the precision is zero and the '#' flag is set, add the
        // requested decimal point.
        if (f.contains(Flags.ALTERNATE) && (prec == 0)) {
          mant = addDot(mant);
        }

        int newW = width;
        if (width != -1) {
          newW = adjustWidth(width, f, neg);
        }
        localizedMagnitude(sb, mant, f, newW, l);
      } else if (c == Conversion.GENERAL) {
        int prec = precision;
        if (precision == -1) {
          prec = 6;
        } else if (precision == 0) {
          prec = 1;
        }

        char[] exp;
        char[] mant;
        int expRounded;
        if (value == 0.0) {
          exp = null;
          mant = new char[]{'0'};
          expRounded = 0;
        } else {
          FormattedFloatingDecimal fd
              = FormattedFloatingDecimal.valueOf(value, prec,
              FormattedFloatingDecimal.Form.GENERAL);
          exp = fd.getExponent();
          mant = fd.getMantissa();
          expRounded = fd.getExponentRounded();
        }

        if (exp != null) {
          prec -= 1;
        } else {
          prec -= expRounded + 1;
        }

        mant = addZeros(mant, prec);
        // If the precision is zero and the '#' flag is set, add the
        // requested decimal point.
        if (f.contains(Flags.ALTERNATE) && (prec == 0)) {
          mant = addDot(mant);
        }

        int newW = width;
        if (width != -1) {
          if (exp != null) {
            newW = adjustWidth(width - exp.length - 1, f, neg);
          } else {
            newW = adjustWidth(width, f, neg);
          }
        }
        localizedMagnitude(sb, mant, f, newW, l);

        if (exp != null) {
          sb.append(f.contains(Flags.UPPERCASE) ? 'E' : 'e');

          Flags flags = f.dup().remove(Flags.GROUP);
          char sign = exp[0];
          assert (sign == '+' || sign == '-');
          sb.append(sign);

          char[] tmp = new char[exp.length - 1];
          System.arraycopy(exp, 1, tmp, 0, exp.length - 1);
          sb.append(localizedMagnitude(null, tmp, flags, -1, l));
        }
      } else if (c == Conversion.HEXADECIMAL_FLOAT) {
        int prec = precision;
        if (precision == -1)
        // assume that we want all of the digits
        {
          prec = 0;
        } else if (precision == 0) {
          prec = 1;
        }

        String s = hexDouble(value, prec);

        char[] va;
        boolean upper = f.contains(Flags.UPPERCASE);
        sb.append(upper ? "0X" : "0x");

        if (f.contains(Flags.ZERO_PAD)) {
          for (int i = 0; i < width - s.length() - 2; i++) {
            sb.append('0');
          }
        }

        int idx = s.indexOf('p');
        va = s.substring(0, idx).toCharArray();
        if (upper) {
          String tmp = new String(va);
          // don't localize hex
          tmp = tmp.toUpperCase(Locale.US);
          va = tmp.toCharArray();
        }
        sb.append(prec != 0 ? addZeros(va, prec) : va);
        sb.append(upper ? 'P' : 'p');
        sb.append(s.substring(idx + 1));
      }
    }

    // Add zeros to the requested precision.
    private char[] addZeros(char[] v, int prec) {
      // Look for the dot.  If we don't find one, the we'll need to add
      // it before we add the zeros.
      int i;
      for (i = 0; i < v.length; i++) {
        if (v[i] == '.') {
          break;
        }
      }
      boolean needDot = false;
      if (i == v.length) {
        needDot = true;
      }

      // Determine existing precision.
      int outPrec = v.length - i - (needDot ? 0 : 1);
      assert (outPrec <= prec);
      if (outPrec == prec) {
        return v;
      }

      // Create new array with existing contents.
      char[] tmp
          = new char[v.length + prec - outPrec + (needDot ? 1 : 0)];
      System.arraycopy(v, 0, tmp, 0, v.length);

      // Add dot if previously determined to be necessary.
      int start = v.length;
      if (needDot) {
        tmp[v.length] = '.';
        start++;
      }

      // Add zeros.
      for (int j = start; j < tmp.length; j++) {
        tmp[j] = '0';
      }

      return tmp;
    }

    // Method assumes that d > 0.
    private String hexDouble(double d, int prec) {
      // Let Double.toHexString handle simple cases
      if (!Double.isFinite(d) || d == 0.0 || prec == 0 || prec >= 13)
      // remove "0x"
      {
        return Double.toHexString(d).substring(2);
      } else {
        assert (prec >= 1 && prec <= 12);

        int exponent = Math.getExponent(d);
        boolean subnormal
            = (exponent == DoubleConsts.MIN_EXPONENT - 1);

        // If this is subnormal input so normalize (could be faster to
        // do as integer operation).
        if (subnormal) {
          scaleUp = Math.scalb(1.0, 54);
          d *= scaleUp;
          // Calculate the exponent.  This is not just exponent + 54
          // since the former is not the normalized exponent.
          exponent = Math.getExponent(d);
          assert exponent >= DoubleConsts.MIN_EXPONENT &&
              exponent <= DoubleConsts.MAX_EXPONENT : exponent;
        }

        int precision = 1 + prec * 4;
        int shiftDistance
            = DoubleConsts.SIGNIFICAND_WIDTH - precision;
        assert (shiftDistance >= 1 && shiftDistance < DoubleConsts.SIGNIFICAND_WIDTH);

        long doppel = Double.doubleToLongBits(d);
        // Deterime the number of bits to keep.
        long newSignif
            = (doppel & (DoubleConsts.EXP_BIT_MASK
            | DoubleConsts.SIGNIF_BIT_MASK))
            >> shiftDistance;
        // Bits to round away.
        long roundingBits = doppel & ~(~0L << shiftDistance);

        // To decide how to round, look at the low-order bit of the
        // working significand, the highest order discarded bit (the
        // round bit) and whether any of the lower order discarded bits
        // are nonzero (the sticky bit).

        boolean leastZero = (newSignif & 0x1L) == 0L;
        boolean round
            = ((1L << (shiftDistance - 1)) & roundingBits) != 0L;
        boolean sticky = shiftDistance > 1 &&
            (~(1L << (shiftDistance - 1)) & roundingBits) != 0;
        if ((leastZero && round && sticky) || (!leastZero && round)) {
          newSignif++;
        }

        long signBit = doppel & DoubleConsts.SIGN_BIT_MASK;
        newSignif = signBit | (newSignif << shiftDistance);
        double result = Double.longBitsToDouble(newSignif);

        if (Double.isInfinite(result)) {
          // Infinite result generated by rounding
          return "1.0p1024";
        } else {
          String res = Double.toHexString(result).substring(2);
          if (!subnormal) {
            return res;
          } else {
            // Create a normalized subnormal string.
            int idx = res.indexOf('p');
            if (idx == -1) {
              // No 'p' character in hex string.
              assert false;
              return null;
            } else {
              // Get exponent and append at the end.
              String exp = res.substring(idx + 1);
              int iexp = Integer.parseInt(exp) - 54;
              return res.substring(0, idx) + "p"
                  + Integer.toString(iexp);
            }
          }
        }
      }
    }

    private void print(BigDecimal value, Locale l) throws IOException {
      if (c == Conversion.HEXADECIMAL_FLOAT) {
        failConversion(c, value);
      }
      StringBuilder sb = new StringBuilder();
      boolean neg = value.signum() == -1;
      BigDecimal v = value.abs();
      // leading sign indicator
      leadingSign(sb, neg);

      // the value
      print(sb, v, l, f, c, precision, neg);

      // trailing sign indicator
      trailingSign(sb, neg);

      // justify based on width
      a.append(justify(sb.toString()));
    }

    // value > 0
    private void print(StringBuilder sb, BigDecimal value, Locale l,
        Flags f, char c, int precision, boolean neg)
        throws IOException {
      if (c == Conversion.SCIENTIFIC) {
        // Create a new BigDecimal with the desired precision.
        int prec = (precision == -1 ? 6 : precision);
        int scale = value.scale();
        int origPrec = value.precision();
        int nzeros = 0;
        int compPrec;

        if (prec > origPrec - 1) {
          compPrec = origPrec;
          nzeros = prec - (origPrec - 1);
        } else {
          compPrec = prec + 1;
        }

        MathContext mc = new MathContext(compPrec);
        BigDecimal v
            = new BigDecimal(value.unscaledValue(), scale, mc);

        BigDecimalLayout bdl
            = new BigDecimalLayout(v.unscaledValue(), v.scale(),
            BigDecimalLayoutForm.SCIENTIFIC);

        char[] mant = bdl.mantissa();

        // Add a decimal point if necessary.  The mantissa may not
        // contain a decimal point if the scale is zero (the internal
        // representation has no fractional part) or the original
        // precision is one. Append a decimal point if '#' is set or if
        // we require zero padding to get to the requested precision.
        if ((origPrec == 1 || !bdl.hasDot())
            && (nzeros > 0 || (f.contains(Flags.ALTERNATE)))) {
          mant = addDot(mant);
        }

        // Add trailing zeros in the case precision is greater than
        // the number of available digits after the decimal separator.
        mant = trailingZeros(mant, nzeros);

        char[] exp = bdl.exponent();
        int newW = width;
        if (width != -1) {
          newW = adjustWidth(width - exp.length - 1, f, neg);
        }
        localizedMagnitude(sb, mant, f, newW, l);

        sb.append(f.contains(Flags.UPPERCASE) ? 'E' : 'e');

        Flags flags = f.dup().remove(Flags.GROUP);
        char sign = exp[0];
        assert (sign == '+' || sign == '-');
        sb.append(exp[0]);

        char[] tmp = new char[exp.length - 1];
        System.arraycopy(exp, 1, tmp, 0, exp.length - 1);
        sb.append(localizedMagnitude(null, tmp, flags, -1, l));
      } else if (c == Conversion.DECIMAL_FLOAT) {
        // Create a new BigDecimal with the desired precision.
        int prec = (precision == -1 ? 6 : precision);
        int scale = value.scale();

        if (scale > prec) {
          // more "scale" digits than the requested "precision"
          int compPrec = value.precision();
          if (compPrec <= scale) {
            // case of 0.xxxxxx
            value = value.setScale(prec, RoundingMode.HALF_UP);
          } else {
            compPrec -= (scale - prec);
            value = new BigDecimal(value.unscaledValue(),
                scale,
                new MathContext(compPrec));
          }
        }
        BigDecimalLayout bdl = new BigDecimalLayout(
            value.unscaledValue(),
            value.scale(),
            BigDecimalLayoutForm.DECIMAL_FLOAT);

        char mant[] = bdl.mantissa();
        int nzeros = (bdl.scale() < prec ? prec - bdl.scale() : 0);

        // Add a decimal point if necessary.  The mantissa may not
        // contain a decimal point if the scale is zero (the internal
        // representation has no fractional part).  Append a decimal
        // point if '#' is set or we require zero padding to get to the
        // requested precision.
        if (bdl.scale() == 0 && (f.contains(Flags.ALTERNATE) || nzeros > 0)) {
          mant = addDot(bdl.mantissa());
        }

        // Add trailing zeros if the precision is greater than the
        // number of available digits after the decimal separator.
        mant = trailingZeros(mant, nzeros);

        localizedMagnitude(sb, mant, f, adjustWidth(width, f, neg), l);
      } else if (c == Conversion.GENERAL) {
        int prec = precision;
        if (precision == -1) {
          prec = 6;
        } else if (precision == 0) {
          prec = 1;
        }

        BigDecimal tenToTheNegFour = BigDecimal.valueOf(1, 4);
        BigDecimal tenToThePrec = BigDecimal.valueOf(1, -prec);
        if ((value.equals(BigDecimal.ZERO))
            || ((value.compareTo(tenToTheNegFour) != -1)
            && (value.compareTo(tenToThePrec) == -1))) {

          int e = -value.scale()
              + (value.unscaledValue().toString().length() - 1);

          // xxx.yyy
          //   g precision (# sig digits) = #x + #y
          //   f precision = #y
          //   exponent = #x - 1
          // => f precision = g precision - exponent - 1
          // 0.000zzz
          //   g precision (# sig digits) = #z
          //   f precision = #0 (after '.') + #z
          //   exponent = - #0 (after '.') - 1
          // => f precision = g precision - exponent - 1
          prec = prec - e - 1;

          print(sb, value, l, f, Conversion.DECIMAL_FLOAT, prec,
              neg);
        } else {
          print(sb, value, l, f, Conversion.SCIENTIFIC, prec - 1, neg);
        }
      } else if (c == Conversion.HEXADECIMAL_FLOAT) {
        // This conversion isn't supported.  The error should be
        // reported earlier.
        assert false;
      }
    }

    private class BigDecimalLayout {

      private StringBuilder mant;
      private StringBuilder exp;
      private boolean dot = false;
      private int scale;

      public BigDecimalLayout(BigInteger intVal, int scale, BigDecimalLayoutForm form) {
        layout(intVal, scale, form);
      }

      public boolean hasDot() {
        return dot;
      }

      public int scale() {
        return scale;
      }

      // char[] with canonical string representation
      public char[] layoutChars() {
        StringBuilder sb = new StringBuilder(mant);
        if (exp != null) {
          sb.append('E');
          sb.append(exp);
        }
        return toCharArray(sb);
      }

      public char[] mantissa() {
        return toCharArray(mant);
      }

      // The exponent will be formatted as a sign ('+' or '-') followed
      // by the exponent zero-padded to include at least two digits.
      public char[] exponent() {
        return toCharArray(exp);
      }

      private char[] toCharArray(StringBuilder sb) {
        if (sb == null) {
          return null;
        }
        char[] result = new char[sb.length()];
        sb.getChars(0, result.length, result, 0);
        return result;
      }

      private void layout(BigInteger intVal, int scale, BigDecimalLayoutForm form) {
        char coeff[] = intVal.toString().toCharArray();
        this.scale = scale;

        // Construct a buffer, with sufficient capacity for all cases.
        // If E-notation is needed, length will be: +1 if negative, +1
        // if '.' needed, +2 for "E+", + up to 10 for adjusted
        // exponent.  Otherwise it could have +1 if negative, plus
        // leading "0.00000"
        mant = new StringBuilder(coeff.length + 14);

        if (scale == 0) {
          int len = coeff.length;
          if (len > 1) {
            mant.append(coeff[0]);
            if (form == BigDecimalLayoutForm.SCIENTIFIC) {
              mant.append('.');
              dot = true;
              mant.append(coeff, 1, len - 1);
              exp = new StringBuilder("+");
              if (len < 10) {
                exp.append("0").append(len - 1);
              } else {
                exp.append(len - 1);
              }
            } else {
              mant.append(coeff, 1, len - 1);
            }
          } else {
            mant.append(coeff);
            if (form == BigDecimalLayoutForm.SCIENTIFIC) {
              exp = new StringBuilder("+00");
            }
          }
          return;
        }
        long adjusted = -(long) scale + (coeff.length - 1);
        if (form == BigDecimalLayoutForm.DECIMAL_FLOAT) {
          // count of padding zeros
          int pad = scale - coeff.length;
          if (pad >= 0) {
            // 0.xxx form
            mant.append("0.");
            dot = true;
            for (; pad > 0; pad--) {
              mant.append('0');
            }
            mant.append(coeff);
          } else {
            if (-pad < coeff.length) {
              // xx.xx form
              mant.append(coeff, 0, -pad);
              mant.append('.');
              dot = true;
              mant.append(coeff, -pad, scale);
            } else {
              // xx form
              mant.append(coeff, 0, coeff.length);
              for (int i = 0; i < -scale; i++) {
                mant.append('0');
              }
              this.scale = 0;
            }
          }
        } else {
          // x.xxx form
          mant.append(coeff[0]);
          if (coeff.length > 1) {
            mant.append('.');
            dot = true;
            mant.append(coeff, 1, coeff.length - 1);
          }
          exp = new StringBuilder();
          if (adjusted != 0) {
            long abs = Math.abs(adjusted);
            // require sign
            exp.append(adjusted < 0 ? '-' : '+');
            if (abs < 10) {
              exp.append('0');
            }
            exp.append(abs);
          } else {
            exp.append("+00");
          }
        }
      }
    }

    private int adjustWidth(int width, Flags f, boolean neg) {
      int newW = width;
      if (newW != -1 && neg && f.contains(Flags.PARENTHESES)) {
        newW--;
      }
      return newW;
    }

    // Add a '.' to th mantissa if required
    private char[] addDot(char[] mant) {
      char[] tmp = mant;
      tmp = new char[mant.length + 1];
      System.arraycopy(mant, 0, tmp, 0, mant.length);
      tmp[tmp.length - 1] = '.';
      return tmp;
    }

    // Add trailing zeros in the case precision is greater than the number
    // of available digits after the decimal separator.
    private char[] trailingZeros(char[] mant, int nzeros) {
      char[] tmp = mant;
      if (nzeros > 0) {
        tmp = new char[mant.length + nzeros];
        System.arraycopy(mant, 0, tmp, 0, mant.length);
        for (int i = mant.length; i < tmp.length; i++) {
          tmp[i] = '0';
        }
      }
      return tmp;
    }

    private void print(Calendar t, char c, Locale l) throws IOException {
      StringBuilder sb = new StringBuilder();
      print(sb, t, c, l);

      // justify based on width
      String s = justify(sb.toString());
      if (f.contains(Flags.UPPERCASE)) {
        s = s.toUpperCase();
      }

      a.append(s);
    }

    private Appendable print(StringBuilder sb, Calendar t, char c,
        Locale l)
        throws IOException {
      if (sb == null) {
        sb = new StringBuilder();
      }
      switch (c) {
        case DateTime.HOUR_OF_DAY_0: // 'H' (00 - 23)
        case DateTime.HOUR_0:        // 'I' (01 - 12)
        case DateTime.HOUR_OF_DAY:   // 'k' (0 - 23) -- like H
        case DateTime.HOUR: { // 'l' (1 - 12) -- like I
          int i = t.get(Calendar.HOUR_OF_DAY);
          if (c == DateTime.HOUR_0 || c == DateTime.HOUR) {
            i = (i == 0 || i == 12 ? 12 : i % 12);
          }
          Flags flags = (c == DateTime.HOUR_OF_DAY_0
              || c == DateTime.HOUR_0
              ? Flags.ZERO_PAD
              : Flags.NONE);
          sb.append(localizedMagnitude(null, i, flags, 2, l));
          break;
        }
        case DateTime.MINUTE: { // 'M' (00 - 59)
          int i = t.get(Calendar.MINUTE);
          Flags flags = Flags.ZERO_PAD;
          sb.append(localizedMagnitude(null, i, flags, 2, l));
          break;
        }
        case DateTime.NANOSECOND: { // 'N' (000000000 - 999999999)
          int i = t.get(Calendar.MILLISECOND) * 1000000;
          Flags flags = Flags.ZERO_PAD;
          sb.append(localizedMagnitude(null, i, flags, 9, l));
          break;
        }
        case DateTime.MILLISECOND: { // 'L' (000 - 999)
          int i = t.get(Calendar.MILLISECOND);
          Flags flags = Flags.ZERO_PAD;
          sb.append(localizedMagnitude(null, i, flags, 3, l));
          break;
        }
        case DateTime.MILLISECOND_SINCE_EPOCH: { // 'Q' (0 - 99...?)
          long i = t.getTimeInMillis();
          Flags flags = Flags.NONE;
          sb.append(localizedMagnitude(null, i, flags, width, l));
          break;
        }
        case DateTime.AM_PM: { // 'p' (am or pm)
          // Calendar.AM = 0, Calendar.PM = 1, LocaleElements defines upper
          String[] ampm = {"AM", "PM"};
          if (l != null && l != Locale.US) {
            DateFormatSymbols dfs = DateFormatSymbols.getInstance(l);
            ampm = dfs.getAmPmStrings();
          }
          String s = ampm[t.get(Calendar.AM_PM)];
          sb.append(s.toLowerCase(l != null ? l : Locale.US));
          break;
        }
        case DateTime.SECONDS_SINCE_EPOCH: { // 's' (0 - 99...?)
          long i = t.getTimeInMillis() / 1000;
          Flags flags = Flags.NONE;
          sb.append(localizedMagnitude(null, i, flags, width, l));
          break;
        }
        case DateTime.SECOND: { // 'S' (00 - 60 - leap second)
          int i = t.get(Calendar.SECOND);
          Flags flags = Flags.ZERO_PAD;
          sb.append(localizedMagnitude(null, i, flags, 2, l));
          break;
        }
        case DateTime.ZONE_NUMERIC: { // 'z' ({-|+}####) - ls minus?
          int i = t.get(Calendar.ZONE_OFFSET) + t.get(Calendar.DST_OFFSET);
          boolean neg = i < 0;
          sb.append(neg ? '-' : '+');
          if (neg) {
            i = -i;
          }
          int min = i / 60000;
          // combine minute and hour into a single integer
          int offset = (min / 60) * 100 + (min % 60);
          Flags flags = Flags.ZERO_PAD;

          sb.append(localizedMagnitude(null, offset, flags, 4, l));
          break;
        }
        case DateTime.ZONE: { // 'Z' (symbol)
          TimeZone tz = t.getTimeZone();
          sb.append(tz.getDisplayName((t.get(Calendar.DST_OFFSET) != 0),
              TimeZone.SHORT,
              (l == null) ? Locale.US : l));
          break;
        }

        // Date
        case DateTime.NAME_OF_DAY_ABBREV:     // 'a'
        case DateTime.NAME_OF_DAY: { // 'A'
          int i = t.get(Calendar.DAY_OF_WEEK);
          Locale lt = ((l == null) ? Locale.US : l);
          DateFormatSymbols dfs = DateFormatSymbols.getInstance(lt);
          if (c == DateTime.NAME_OF_DAY) {
            sb.append(dfs.getWeekdays()[i]);
          } else {
            sb.append(dfs.getShortWeekdays()[i]);
          }
          break;
        }
        case DateTime.NAME_OF_MONTH_ABBREV:   // 'b'
        case DateTime.NAME_OF_MONTH_ABBREV_X: // 'h' -- same b
        case DateTime.NAME_OF_MONTH: { // 'B'
          int i = t.get(Calendar.MONTH);
          Locale lt = ((l == null) ? Locale.US : l);
          DateFormatSymbols dfs = DateFormatSymbols.getInstance(lt);
          if (c == DateTime.NAME_OF_MONTH) {
            sb.append(dfs.getMonths()[i]);
          } else {
            sb.append(dfs.getShortMonths()[i]);
          }
          break;
        }
        case DateTime.CENTURY:                // 'C' (00 - 99)
        case DateTime.YEAR_2:                 // 'y' (00 - 99)
        case DateTime.YEAR_4: { // 'Y' (0000 - 9999)
          int i = t.get(Calendar.YEAR);
          int size = 2;
          switch (c) {
            case DateTime.CENTURY:
              i /= 100;
              break;
            case DateTime.YEAR_2:
              i %= 100;
              break;
            case DateTime.YEAR_4:
              size = 4;
              break;
          }
          Flags flags = Flags.ZERO_PAD;
          sb.append(localizedMagnitude(null, i, flags, size, l));
          break;
        }
        case DateTime.DAY_OF_MONTH_0:         // 'd' (01 - 31)
        case DateTime.DAY_OF_MONTH: { // 'e' (1 - 31) -- like d
          int i = t.get(Calendar.DATE);
          Flags flags = (c == DateTime.DAY_OF_MONTH_0
              ? Flags.ZERO_PAD
              : Flags.NONE);
          sb.append(localizedMagnitude(null, i, flags, 2, l));
          break;
        }
        case DateTime.DAY_OF_YEAR: { // 'j' (001 - 366)
          int i = t.get(Calendar.DAY_OF_YEAR);
          Flags flags = Flags.ZERO_PAD;
          sb.append(localizedMagnitude(null, i, flags, 3, l));
          break;
        }
        case DateTime.MONTH: { // 'm' (01 - 12)
          int i = t.get(Calendar.MONTH) + 1;
          Flags flags = Flags.ZERO_PAD;
          sb.append(localizedMagnitude(null, i, flags, 2, l));
          break;
        }

        // Composites
        case DateTime.TIME:         // 'T' (24 hour hh:mm:ss - %tH:%tM:%tS)
        case DateTime.TIME_24_HOUR: { // 'R' (hh:mm same as %H:%M)
          char sep = ':';
          print(sb, t, DateTime.HOUR_OF_DAY_0, l).append(sep);
          print(sb, t, DateTime.MINUTE, l);
          if (c == DateTime.TIME) {
            sb.append(sep);
            print(sb, t, DateTime.SECOND, l);
          }
          break;
        }
        case DateTime.TIME_12_HOUR: { // 'r' (hh:mm:ss [AP]M)
          char sep = ':';
          print(sb, t, DateTime.HOUR_0, l).append(sep);
          print(sb, t, DateTime.MINUTE, l).append(sep);
          print(sb, t, DateTime.SECOND, l).append(' ');
          // this may be in wrong place for some locales
          StringBuilder tsb = new StringBuilder();
          print(tsb, t, DateTime.AM_PM, l);
          sb.append(tsb.toString().toUpperCase(l != null ? l : Locale.US));
          break;
        }
        case DateTime.DATE_TIME: { // 'c' (Sat Nov 04 12:02:33 EST 1999)
          char sep = ' ';
          print(sb, t, DateTime.NAME_OF_DAY_ABBREV, l).append(sep);
          print(sb, t, DateTime.NAME_OF_MONTH_ABBREV, l).append(sep);
          print(sb, t, DateTime.DAY_OF_MONTH_0, l).append(sep);
          print(sb, t, DateTime.TIME, l).append(sep);
          print(sb, t, DateTime.ZONE, l).append(sep);
          print(sb, t, DateTime.YEAR_4, l);
          break;
        }
        case DateTime.DATE: { // 'D' (mm/dd/yy)
          char sep = '/';
          print(sb, t, DateTime.MONTH, l).append(sep);
          print(sb, t, DateTime.DAY_OF_MONTH_0, l).append(sep);
          print(sb, t, DateTime.YEAR_2, l);
          break;
        }
        case DateTime.ISO_STANDARD_DATE: { // 'F' (%Y-%m-%d)
          char sep = '-';
          print(sb, t, DateTime.YEAR_4, l).append(sep);
          print(sb, t, DateTime.MONTH, l).append(sep);
          print(sb, t, DateTime.DAY_OF_MONTH_0, l);
          break;
        }
        default:
          assert false;
      }
      return sb;
    }

    private void print(TemporalAccessor t, char c, Locale l) throws IOException {
      StringBuilder sb = new StringBuilder();
      print(sb, t, c, l);
      // justify based on width
      String s = justify(sb.toString());
      if (f.contains(Flags.UPPERCASE)) {
        s = s.toUpperCase();
      }
      a.append(s);
    }

    private Appendable print(StringBuilder sb, TemporalAccessor t, char c,
        Locale l) throws IOException {
      if (sb == null) {
        sb = new StringBuilder();
      }
      try {
        switch (c) {
          case DateTime.HOUR_OF_DAY_0: {  // 'H' (00 - 23)
            int i = t.get(ChronoField.HOUR_OF_DAY);
            sb.append(localizedMagnitude(null, i, Flags.ZERO_PAD, 2, l));
            break;
          }
          case DateTime.HOUR_OF_DAY: {   // 'k' (0 - 23) -- like H
            int i = t.get(ChronoField.HOUR_OF_DAY);
            sb.append(localizedMagnitude(null, i, Flags.NONE, 2, l));
            break;
          }
          case DateTime.HOUR_0: {  // 'I' (01 - 12)
            int i = t.get(ChronoField.CLOCK_HOUR_OF_AMPM);
            sb.append(localizedMagnitude(null, i, Flags.ZERO_PAD, 2, l));
            break;
          }
          case DateTime.HOUR: { // 'l' (1 - 12) -- like I
            int i = t.get(ChronoField.CLOCK_HOUR_OF_AMPM);
            sb.append(localizedMagnitude(null, i, Flags.NONE, 2, l));
            break;
          }
          case DateTime.MINUTE: { // 'M' (00 - 59)
            int i = t.get(ChronoField.MINUTE_OF_HOUR);
            Flags flags = Flags.ZERO_PAD;
            sb.append(localizedMagnitude(null, i, flags, 2, l));
            break;
          }
          case DateTime.NANOSECOND: { // 'N' (000000000 - 999999999)
            int i = t.get(ChronoField.MILLI_OF_SECOND) * 1000000;
            Flags flags = Flags.ZERO_PAD;
            sb.append(localizedMagnitude(null, i, flags, 9, l));
            break;
          }
          case DateTime.MILLISECOND: { // 'L' (000 - 999)
            int i = t.get(ChronoField.MILLI_OF_SECOND);
            Flags flags = Flags.ZERO_PAD;
            sb.append(localizedMagnitude(null, i, flags, 3, l));
            break;
          }
          case DateTime.MILLISECOND_SINCE_EPOCH: { // 'Q' (0 - 99...?)
            long i = t.getLong(ChronoField.INSTANT_SECONDS) * 1000L +
                t.getLong(ChronoField.MILLI_OF_SECOND);
            Flags flags = Flags.NONE;
            sb.append(localizedMagnitude(null, i, flags, width, l));
            break;
          }
          case DateTime.AM_PM: { // 'p' (am or pm)
            // Calendar.AM = 0, Calendar.PM = 1, LocaleElements defines upper
            String[] ampm = {"AM", "PM"};
            if (l != null && l != Locale.US) {
              DateFormatSymbols dfs = DateFormatSymbols.getInstance(l);
              ampm = dfs.getAmPmStrings();
            }
            String s = ampm[t.get(ChronoField.AMPM_OF_DAY)];
            sb.append(s.toLowerCase(l != null ? l : Locale.US));
            break;
          }
          case DateTime.SECONDS_SINCE_EPOCH: { // 's' (0 - 99...?)
            long i = t.getLong(ChronoField.INSTANT_SECONDS);
            Flags flags = Flags.NONE;
            sb.append(localizedMagnitude(null, i, flags, width, l));
            break;
          }
          case DateTime.SECOND: { // 'S' (00 - 60 - leap second)
            int i = t.get(ChronoField.SECOND_OF_MINUTE);
            Flags flags = Flags.ZERO_PAD;
            sb.append(localizedMagnitude(null, i, flags, 2, l));
            break;
          }
          case DateTime.ZONE_NUMERIC: { // 'z' ({-|+}####) - ls minus?
            int i = t.get(ChronoField.OFFSET_SECONDS);
            boolean neg = i < 0;
            sb.append(neg ? '-' : '+');
            if (neg) {
              i = -i;
            }
            int min = i / 60;
            // combine minute and hour into a single integer
            int offset = (min / 60) * 100 + (min % 60);
            Flags flags = Flags.ZERO_PAD;
            sb.append(localizedMagnitude(null, offset, flags, 4, l));
            break;
          }
          case DateTime.ZONE: { // 'Z' (symbol)
            ZoneId zid = t.query(TemporalQueries.zone());
            if (zid == null) {
              throw new IllegalFormatConversionException(c, t.getClass());
            }
            if (!(zid instanceof ZoneOffset) &&
                t.isSupported(ChronoField.INSTANT_SECONDS)) {
              Instant instant = Instant.from(t);
              sb.append(TimeZone.getTimeZone(zid.getId())
                  .getDisplayName(zid.getRules().isDaylightSavings(instant),
                      TimeZone.SHORT,
                      (l == null) ? Locale.US : l));
              break;
            }
            sb.append(zid.getId());
            break;
          }
          // Date
          case DateTime.NAME_OF_DAY_ABBREV:     // 'a'
          case DateTime.NAME_OF_DAY: { // 'A'
            int i = t.get(ChronoField.DAY_OF_WEEK) % 7 + 1;
            Locale lt = ((l == null) ? Locale.US : l);
            DateFormatSymbols dfs = DateFormatSymbols.getInstance(lt);
            if (c == DateTime.NAME_OF_DAY) {
              sb.append(dfs.getWeekdays()[i]);
            } else {
              sb.append(dfs.getShortWeekdays()[i]);
            }
            break;
          }
          case DateTime.NAME_OF_MONTH_ABBREV:   // 'b'
          case DateTime.NAME_OF_MONTH_ABBREV_X: // 'h' -- same b
          case DateTime.NAME_OF_MONTH: { // 'B'
            int i = t.get(ChronoField.MONTH_OF_YEAR) - 1;
            Locale lt = ((l == null) ? Locale.US : l);
            DateFormatSymbols dfs = DateFormatSymbols.getInstance(lt);
            if (c == DateTime.NAME_OF_MONTH) {
              sb.append(dfs.getMonths()[i]);
            } else {
              sb.append(dfs.getShortMonths()[i]);
            }
            break;
          }
          case DateTime.CENTURY:                // 'C' (00 - 99)
          case DateTime.YEAR_2:                 // 'y' (00 - 99)
          case DateTime.YEAR_4: { // 'Y' (0000 - 9999)
            int i = t.get(ChronoField.YEAR_OF_ERA);
            int size = 2;
            switch (c) {
              case DateTime.CENTURY:
                i /= 100;
                break;
              case DateTime.YEAR_2:
                i %= 100;
                break;
              case DateTime.YEAR_4:
                size = 4;
                break;
            }
            Flags flags = Flags.ZERO_PAD;
            sb.append(localizedMagnitude(null, i, flags, size, l));
            break;
          }
          case DateTime.DAY_OF_MONTH_0:         // 'd' (01 - 31)
          case DateTime.DAY_OF_MONTH: { // 'e' (1 - 31) -- like d
            int i = t.get(ChronoField.DAY_OF_MONTH);
            Flags flags = (c == DateTime.DAY_OF_MONTH_0
                ? Flags.ZERO_PAD
                : Flags.NONE);
            sb.append(localizedMagnitude(null, i, flags, 2, l));
            break;
          }
          case DateTime.DAY_OF_YEAR: { // 'j' (001 - 366)
            int i = t.get(ChronoField.DAY_OF_YEAR);
            Flags flags = Flags.ZERO_PAD;
            sb.append(localizedMagnitude(null, i, flags, 3, l));
            break;
          }
          case DateTime.MONTH: { // 'm' (01 - 12)
            int i = t.get(ChronoField.MONTH_OF_YEAR);
            Flags flags = Flags.ZERO_PAD;
            sb.append(localizedMagnitude(null, i, flags, 2, l));
            break;
          }

          // Composites
          case DateTime.TIME:         // 'T' (24 hour hh:mm:ss - %tH:%tM:%tS)
          case DateTime.TIME_24_HOUR: { // 'R' (hh:mm same as %H:%M)
            char sep = ':';
            print(sb, t, DateTime.HOUR_OF_DAY_0, l).append(sep);
            print(sb, t, DateTime.MINUTE, l);
            if (c == DateTime.TIME) {
              sb.append(sep);
              print(sb, t, DateTime.SECOND, l);
            }
            break;
          }
          case DateTime.TIME_12_HOUR: { // 'r' (hh:mm:ss [AP]M)
            char sep = ':';
            print(sb, t, DateTime.HOUR_0, l).append(sep);
            print(sb, t, DateTime.MINUTE, l).append(sep);
            print(sb, t, DateTime.SECOND, l).append(' ');
            // this may be in wrong place for some locales
            StringBuilder tsb = new StringBuilder();
            print(tsb, t, DateTime.AM_PM, l);
            sb.append(tsb.toString().toUpperCase(l != null ? l : Locale.US));
            break;
          }
          case DateTime.DATE_TIME: { // 'c' (Sat Nov 04 12:02:33 EST 1999)
            char sep = ' ';
            print(sb, t, DateTime.NAME_OF_DAY_ABBREV, l).append(sep);
            print(sb, t, DateTime.NAME_OF_MONTH_ABBREV, l).append(sep);
            print(sb, t, DateTime.DAY_OF_MONTH_0, l).append(sep);
            print(sb, t, DateTime.TIME, l).append(sep);
            print(sb, t, DateTime.ZONE, l).append(sep);
            print(sb, t, DateTime.YEAR_4, l);
            break;
          }
          case DateTime.DATE: { // 'D' (mm/dd/yy)
            char sep = '/';
            print(sb, t, DateTime.MONTH, l).append(sep);
            print(sb, t, DateTime.DAY_OF_MONTH_0, l).append(sep);
            print(sb, t, DateTime.YEAR_2, l);
            break;
          }
          case DateTime.ISO_STANDARD_DATE: { // 'F' (%Y-%m-%d)
            char sep = '-';
            print(sb, t, DateTime.YEAR_4, l).append(sep);
            print(sb, t, DateTime.MONTH, l).append(sep);
            print(sb, t, DateTime.DAY_OF_MONTH_0, l);
            break;
          }
          default:
            assert false;
        }
      } catch (DateTimeException x) {
        throw new IllegalFormatConversionException(c, t.getClass());
      }
      return sb;
    }

    // -- Methods to support throwing exceptions --

    private void failMismatch(Flags f, char c) {
      String fs = f.toString();
      throw new FormatFlagsConversionMismatchException(fs, c);
    }

    private void failConversion(char c, Object arg) {
      throw new IllegalFormatConversionException(c, arg.getClass());
    }

    private char getZero(Locale l) {
      if ((l != null) && !l.equals(locale())) {
        DecimalFormatSymbols dfs = DecimalFormatSymbols.getInstance(l);
        return dfs.getZeroDigit();
      }
      return zero;
    }

    private StringBuilder
    localizedMagnitude(StringBuilder sb, long value, Flags f,
        int width, Locale l) {
      char[] va = Long.toString(value, 10).toCharArray();
      return localizedMagnitude(sb, va, f, width, l);
    }

    private StringBuilder
    localizedMagnitude(StringBuilder sb, char[] value, Flags f,
        int width, Locale l) {
      if (sb == null) {
        sb = new StringBuilder();
      }
      int begin = sb.length();

      char zero = getZero(l);

      // determine localized grouping separator and size
      char grpSep = '\0';
      int grpSize = -1;
      char decSep = '\0';

      int len = value.length;
      int dot = len;
      for (int j = 0; j < len; j++) {
        if (value[j] == '.') {
          dot = j;
          break;
        }
      }

      if (dot < len) {
        if (l == null || l.equals(Locale.US)) {
          decSep = '.';
        } else {
          DecimalFormatSymbols dfs = DecimalFormatSymbols.getInstance(l);
          decSep = dfs.getDecimalSeparator();
        }
      }

      if (f.contains(Flags.GROUP)) {
        if (l == null || l.equals(Locale.US)) {
          grpSep = ',';
          grpSize = 3;
        } else {
          DecimalFormatSymbols dfs = DecimalFormatSymbols.getInstance(l);
          grpSep = dfs.getGroupingSeparator();
          DecimalFormat df = (DecimalFormat) NumberFormat.getIntegerInstance(l);
          grpSize = df.getGroupingSize();
        }
      }

      // localize the digits inserting group separators as necessary
      for (int j = 0; j < len; j++) {
        if (j == dot) {
          sb.append(decSep);
          // no more group separators after the decimal separator
          grpSep = '\0';
          continue;
        }

        char c = value[j];
        sb.append((char) ((c - '0') + zero));
        if (grpSep != '\0' && j != dot - 1 && ((dot - j) % grpSize == 1)) {
          sb.append(grpSep);
        }
      }

      // apply zero padding
      len = sb.length();
      if (width != -1 && f.contains(Flags.ZERO_PAD)) {
        for (int k = 0; k < width - len; k++) {
          sb.insert(begin, zero);
        }
      }

      return sb;
    }
  }

  private static class Flags {

    private int flags;

    static final Flags NONE = new Flags(0);      // ''

    // duplicate declarations from Formattable.java
    static final Flags LEFT_JUSTIFY = new Flags(1 << 0);   // '-'
    static final Flags UPPERCASE = new Flags(1 << 1);   // '^'
    static final Flags ALTERNATE = new Flags(1 << 2);   // '#'

    // numerics
    static final Flags PLUS = new Flags(1 << 3);   // '+'
    static final Flags LEADING_SPACE = new Flags(1 << 4);   // ' '
    static final Flags ZERO_PAD = new Flags(1 << 5);   // '0'
    static final Flags GROUP = new Flags(1 << 6);   // ','
    static final Flags PARENTHESES = new Flags(1 << 7);   // '('

    // indexing
    static final Flags PREVIOUS = new Flags(1 << 8);   // '<'

    private Flags(int f) {
      flags = f;
    }

    public int valueOf() {
      return flags;
    }

    public boolean contains(Flags f) {
      return (flags & f.valueOf()) == f.valueOf();
    }

    public Flags dup() {
      return new Flags(flags);
    }

    private Flags add(Flags f) {
      flags |= f.valueOf();
      return this;
    }

    public Flags remove(Flags f) {
      flags &= ~f.valueOf();
      return this;
    }

    public static Flags parse(String s) {
      char[] ca = s.toCharArray();
      Flags f = new Flags(0);
      for (int i = 0; i < ca.length; i++) {
        Flags v = parse(ca[i]);
        if (f.contains(v)) {
          throw new DuplicateFormatFlagsException(v.toString());
        }
        f.add(v);
      }
      return f;
    }

    // parse those flags which may be provided by users
    private static Flags parse(char c) {
      switch (c) {
        case '-':
          return LEFT_JUSTIFY;
        case '#':
          return ALTERNATE;
        case '+':
          return PLUS;
        case ' ':
          return LEADING_SPACE;
        case '0':
          return ZERO_PAD;
        case ',':
          return GROUP;
        case '(':
          return PARENTHESES;
        case '<':
          return PREVIOUS;
        default:
          throw new UnknownFormatFlagsException(String.valueOf(c));
      }
    }

    // Returns a string representation of the current {@code Flags}.
    public static String toString(Flags f) {
      return f.toString();
    }

    public String toString() {
      StringBuilder sb = new StringBuilder();
      if (contains(LEFT_JUSTIFY)) {
        sb.append('-');
      }
      if (contains(UPPERCASE)) {
        sb.append('^');
      }
      if (contains(ALTERNATE)) {
        sb.append('#');
      }
      if (contains(PLUS)) {
        sb.append('+');
      }
      if (contains(LEADING_SPACE)) {
        sb.append(' ');
      }
      if (contains(ZERO_PAD)) {
        sb.append('0');
      }
      if (contains(GROUP)) {
        sb.append(',');
      }
      if (contains(PARENTHESES)) {
        sb.append('(');
      }
      if (contains(PREVIOUS)) {
        sb.append('<');
      }
      return sb.toString();
    }
  }

  private static class Conversion {

    // Byte, Short, Integer, Long, BigInteger
    // (and associated primitives due to autoboxing)
    static final char DECIMAL_INTEGER = 'd';
    static final char OCTAL_INTEGER = 'o';
    static final char HEXADECIMAL_INTEGER = 'x';
    static final char HEXADECIMAL_INTEGER_UPPER = 'X';

    // Float, Double, BigDecimal
    // (and associated primitives due to autoboxing)
    static final char SCIENTIFIC = 'e';
    static final char SCIENTIFIC_UPPER = 'E';
    static final char GENERAL = 'g';
    static final char GENERAL_UPPER = 'G';
    static final char DECIMAL_FLOAT = 'f';
    static final char HEXADECIMAL_FLOAT = 'a';
    static final char HEXADECIMAL_FLOAT_UPPER = 'A';

    // Character, Byte, Short, Integer
    // (and associated primitives due to autoboxing)
    static final char CHARACTER = 'c';
    static final char CHARACTER_UPPER = 'C';

    // java.util.Date, java.util.Calendar, long
    static final char DATE_TIME = 't';
    static final char DATE_TIME_UPPER = 'T';

    // if (arg.TYPE != boolean) return boolean
    // if (arg != null) return true; else return false;
    static final char BOOLEAN = 'b';
    static final char BOOLEAN_UPPER = 'B';
    // if (arg instanceof Formattable) arg.formatTo()
    // else arg.toString();
    static final char STRING = 's';
    static final char STRING_UPPER = 'S';
    // arg.hashCode()
    static final char HASHCODE = 'h';
    static final char HASHCODE_UPPER = 'H';

    static final char LINE_SEPARATOR = 'n';
    static final char PERCENT_SIGN = '%';

    static boolean isValid(char c) {
      return (isGeneral(c) || isInteger(c) || isFloat(c) || isText(c)
          || c == 't' || isCharacter(c));
    }

    // Returns true iff the Conversion is applicable to all objects.
    static boolean isGeneral(char c) {
      switch (c) {
        case BOOLEAN:
        case BOOLEAN_UPPER:
        case STRING:
        case STRING_UPPER:
        case HASHCODE:
        case HASHCODE_UPPER:
          return true;
        default:
          return false;
      }
    }

    // Returns true iff the Conversion is applicable to character.
    static boolean isCharacter(char c) {
      switch (c) {
        case CHARACTER:
        case CHARACTER_UPPER:
          return true;
        default:
          return false;
      }
    }

    // Returns true iff the Conversion is an integer type.
    static boolean isInteger(char c) {
      switch (c) {
        case DECIMAL_INTEGER:
        case OCTAL_INTEGER:
        case HEXADECIMAL_INTEGER:
        case HEXADECIMAL_INTEGER_UPPER:
          return true;
        default:
          return false;
      }
    }

    // Returns true iff the Conversion is a floating-point type.
    static boolean isFloat(char c) {
      switch (c) {
        case SCIENTIFIC:
        case SCIENTIFIC_UPPER:
        case GENERAL:
        case GENERAL_UPPER:
        case DECIMAL_FLOAT:
        case HEXADECIMAL_FLOAT:
        case HEXADECIMAL_FLOAT_UPPER:
          return true;
        default:
          return false;
      }
    }

    // Returns true iff the Conversion does not require an argument
    static boolean isText(char c) {
      switch (c) {
        case LINE_SEPARATOR:
        case PERCENT_SIGN:
          return true;
        default:
          return false;
      }
    }
  }

  private static class DateTime {

    static final char HOUR_OF_DAY_0 = 'H'; // (00 - 23)
    static final char HOUR_0 = 'I'; // (01 - 12)
    static final char HOUR_OF_DAY = 'k'; // (0 - 23) -- like H
    static final char HOUR = 'l'; // (1 - 12) -- like I
    static final char MINUTE = 'M'; // (00 - 59)
    static final char NANOSECOND = 'N'; // (000000000 - 999999999)
    static final char MILLISECOND = 'L'; // jdk, not in gnu (000 - 999)
    static final char MILLISECOND_SINCE_EPOCH = 'Q'; // (0 - 99...?)
    static final char AM_PM = 'p'; // (am or pm)
    static final char SECONDS_SINCE_EPOCH = 's'; // (0 - 99...?)
    static final char SECOND = 'S'; // (00 - 60 - leap second)
    static final char TIME = 'T'; // (24 hour hh:mm:ss)
    static final char ZONE_NUMERIC = 'z'; // (-1200 - +1200) - ls minus?
    static final char ZONE = 'Z'; // (symbol)

    // Date
    static final char NAME_OF_DAY_ABBREV = 'a'; // 'a'
    static final char NAME_OF_DAY = 'A'; // 'A'
    static final char NAME_OF_MONTH_ABBREV = 'b'; // 'b'
    static final char NAME_OF_MONTH = 'B'; // 'B'
    static final char CENTURY = 'C'; // (00 - 99)
    static final char DAY_OF_MONTH_0 = 'd'; // (01 - 31)
    static final char DAY_OF_MONTH = 'e'; // (1 - 31) -- like d
    // *    static final char ISO_WEEK_OF_YEAR_2    = 'g'; // cross %y %V
// *    static final char ISO_WEEK_OF_YEAR_4    = 'G'; // cross %Y %V
    static final char NAME_OF_MONTH_ABBREV_X = 'h'; // -- same b
    static final char DAY_OF_YEAR = 'j'; // (001 - 366)
    static final char MONTH = 'm'; // (01 - 12)
    // *    static final char DAY_OF_WEEK_1         = 'u'; // (1 - 7) Monday
// *    static final char WEEK_OF_YEAR_SUNDAY   = 'U'; // (0 - 53) Sunday+
// *    static final char WEEK_OF_YEAR_MONDAY_01 = 'V'; // (01 - 53) Monday+
// *    static final char DAY_OF_WEEK_0         = 'w'; // (0 - 6) Sunday
// *    static final char WEEK_OF_YEAR_MONDAY   = 'W'; // (00 - 53) Monday
    static final char YEAR_2 = 'y'; // (00 - 99)
    static final char YEAR_4 = 'Y'; // (0000 - 9999)

    // Composites
    static final char TIME_12_HOUR = 'r'; // (hh:mm:ss [AP]M)
    static final char TIME_24_HOUR = 'R'; // (hh:mm same as %H:%M)
    // *    static final char LOCALE_TIME   = 'X'; // (%H:%M:%S) - parse format?
    static final char DATE_TIME = 'c';
    // (Sat Nov 04 12:02:33 EST 1999)
    static final char DATE = 'D'; // (mm/dd/yy)
    static final char ISO_STANDARD_DATE = 'F'; // (%Y-%m-%d)
// *    static final char LOCALE_DATE           = 'x'; // (mm/dd/yy)

    static boolean isValid(char c) {
      switch (c) {
        case HOUR_OF_DAY_0:
        case HOUR_0:
        case HOUR_OF_DAY:
        case HOUR:
        case MINUTE:
        case NANOSECOND:
        case MILLISECOND:
        case MILLISECOND_SINCE_EPOCH:
        case AM_PM:
        case SECONDS_SINCE_EPOCH:
        case SECOND:
        case TIME:
        case ZONE_NUMERIC:
        case ZONE:

          // Date
        case NAME_OF_DAY_ABBREV:
        case NAME_OF_DAY:
        case NAME_OF_MONTH_ABBREV:
        case NAME_OF_MONTH:
        case CENTURY:
        case DAY_OF_MONTH_0:
        case DAY_OF_MONTH:
// *        case ISO_WEEK_OF_YEAR_2:
// *        case ISO_WEEK_OF_YEAR_4:
        case NAME_OF_MONTH_ABBREV_X:
        case DAY_OF_YEAR:
        case MONTH:
// *        case DAY_OF_WEEK_1:
// *        case WEEK_OF_YEAR_SUNDAY:
// *        case WEEK_OF_YEAR_MONDAY_01:
// *        case DAY_OF_WEEK_0:
// *        case WEEK_OF_YEAR_MONDAY:
        case YEAR_2:
        case YEAR_4:

          // Composites
        case TIME_12_HOUR:
        case TIME_24_HOUR:
// *        case LOCALE_TIME:
        case DATE_TIME:
        case DATE:
        case ISO_STANDARD_DATE:
// *        case LOCALE_DATE:
          return true;
        default:
          return false;
      }
    }
  }
}
